Endangered Species Dating Profile: White Abalone

I intended to start a series of this kind of post with other endangered species, but applying for grad school, turning 21, and too many bs excuses got in the way. I will reboot this eventually! Enjoy the personal details of the beautiful White Abalone below!

BASIC INFO

Speices: Haliotis sorenseni

Nickname: White abalone

Picture: When cleaned up, looks like this:

abalonee

But you probably see them like this:

Material 100% Natural White MOP shell Size Numerous small thin shells Length 17 inches Clasp Standard Clasp 35

But actually in the wild, they look like this:

white abalone in wild

Occupation: Gastropod, The Snail/Slug & Co.

Height: 5-8 inches

Weight: 1.7lbs

Age (lifespan): 35-40 years

Hometown: western coast of northern Mexico and southern California, not looking to move any time soon

INTERESTS/HOBBIES

Favorite food: algae, specifically drift macroalgae and red algae – yum!

kelp-o

Favorite show: The Last Man on EarthThis show is so relate-able, considering the density of me and my species is so low that we can barely reproduce – let alone choose who we reproduce with. Even when I’d think I’d never mate with someone even if he was the last man on Earth – let me tell you, it’s not just a phrase, it’s a reality – which brings me here.

Favorite color: shiny white – so shiny and pretty that people use my shells for jewelry.

Hobbies: deep sea diving – I’m the deepest abalone species in the world (living at 80-100ft), rock climbing (I live on rocks), reading Medieval romantic literature, and taking angsty, hipster selfies.

Zodiac Sign: Sagittarius

About Me (aka my baggage)

Not to sound vain or anything, but my main problem is that I am too beautiful for my own good. I clean up very well, you could say. Mexicans of the north love to just take hundreds of me out of the water, scrub off the algae growing on me, and turn me into lovely jewelry.

white abalone jewelry

This has caused populations of me and my kind to reduce by 99%. Our density used to be 1 of us per meter-squared (1/m2), now we’re down to 1 of us per hectare (1/10,000m2).

This decimation has led to another issue area for us: sex.

Sadly, Viagara and other enhancement remedies can’t fix the problem. We are broadcast spawners, meaning that we release our eggs/sperm into the water, hoping they come into contact with and fertilize a different individual’s egg/sperm – talk about PDA!

abalone spawning(Such x-rated material pictured above – abalone porn stars openly spawning)

But because we are loners and our population density is so low, eggs and sperm between different individuals rarely meet and fertilize. So no new babies of us are made, causing our population size to exponentially decrease, as we are harvested from the sea.

On top of that, we tend to get sick with various infections.

My ideal partner: I’m looking for someone who is really down-to-earth and understands me. Ya know? Someone willing to boycott abalone jewelry sales. Even better, I would love to share my life with someone apart of the White Abalone Restoration Consortium. This group is currently helping me and my buds out by regulating the fishing of abalone and increasing our numbers in the wild through captive breeding – breeding us in aquariums and then setting us free. I’m also looking for someone who’s ready to settle down, as I plan on having a family some day to repopulate my decimated bunch.

Think I’m the one for you? Email me at sexyabalone@shellyeah.com

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Got COTS?

**Disclaimer: Poor internet connection restricted my ability to add graphics and gifs. I’m deeply sorry for the absence of Spongebob in this post.**

Paper: Hock, K., Wolff, N. H., Condie, S. A., Anthony, K., & Mumby, P. J. (2014). Connectivity networks reveal the risks of crown‐of‐thorns starfish outbreaks on the Great Barrier Reef. Journal of Applied Ecology, 51(5), 1188-1196.

Have you ever seen something so beautiful, you could cry?

nutella jugSame.

But I’m actually talking about something so beautiful yet so awful.

cots2

This beaut is a Crown-of-Thorns Starfish – a COTS. And it’s the worst.

the-worst

COTS can wreak havoc on coral reefs during outbreaks. An outbreak is when the density of COTS on a reef exceeds the amount of food available to the COTS. And unfortunately, COTS like to eat coral.

Gobbling up a lot of a reef’s coral is extremely detrimental to the reef. Reef-building coral are the ecosystem engineers of reefs. They do not have a degree in physics, but they are a major component of habitat substrate in reefs. Their nooks and crannies provide places for prey, such as different types of fish and critters, to hide from predators, like sharks. Thus, coral is smart, coral is kind, but actually tho – coral is important.

So you might be thinking COTS outbreaks are the most terrible thing ever, but COTS outbreaks are actually like wildfires.

But aren’t wildfires bad?

No.

Wildfires can actually be a good thing. They kill off a lot of vegetation, but then new vegetation can grow. There’s a whole ecological concept behind what I just said, but you’re sick of my ramblings from last week so just google: intermediate disturbance hypothesis I linked he wikipedia article to that for you because I love and want you to be happy.

Similar to how the destruction of vegetation in forests can be a good thing, the destruction of coral by COTS in reefs can be a good thing.

HOWEVER. 

Ocean warming, ocean acidification, pollution, and other whatnot that have resulted from our treating the ocean like a garbage can intensify COTS outbreaks to the point where it gets really, really hard for a reef to recover before the next outbreak.

This study looked at COTS outbreaks in the Great Barrier Reef, which I’ll refer to as GBR because acronyms are the best.

COTS outbreaks in the GBR are mainly a local thing. —you wouldn’t understand—jk jk.

What I mean by local is that COTS are NOT eating up all the coral on the seafloor in the Great Barrier Reef like a vacuum sucking up all the stuff on a carpet.

No no no no.

They mainly just eat up the coral in the reef of their roots.

So how are COTS outbreaks a threat to so many reefs in the Great Barrier Reef (GBR)?

Like many marine critters, COTS produce planktonic larvae – larvae that goes with the flow, and rides with the tides, to wherever they begin to grow.

COTS larvae can travel in the water column from 9 to 42 days. What a huge range!!

So they have the potential to end up in pretty far places from their birth (making sure to call Mom at least every Sunday). Which means they can end up in new reefs, ready to prey on the untouched coral there. How delicious.

Reefs that have a lot of COTSs can lead to COTSs outbreaks. Outbreaks have been documented to occur in Cooktown-Cairns – northern end of the GBR and Swains region – southern end of GBR.

This study aimed to see how connectivity between reefs influenced a reef’s potential threat of COTS outbreak and predict COTS epidemics.

A COTS epidemic is the spreading of COTS outbreaks through connectivity between reefs.

A major theme of this study is POPULATION CONNECTIVITY.

I’m gonna focus on one point of the study because I’m already at 622 words and you’re proabably already bored.

Hypothesis: Reefs with connections to many other reefs have greater potential for COTS outbreaks.

What they did: This study was kinda math-y.Since larvae disperse in the water and “ride with the tide,” they generated simulations on a computer of larvae moving in water. Larvae were represented as particles. They used data collected from the spawning seasons of COTSs from 2006 til 2011.

Each reef was represented by a polygon and 10,000 particles representing COTS larvae were dispersed from each reef in the model. Since the larvae travel at such a range of time length, like I had mentioned above, the model generated larval movement over 28 days – as a compromise of the range.

The connectivity network was then analyzed. Arrows went between reefs representing the movement of a larva from one reef to another during the simulation. The more arrows incoming to a reef, the more larvae that reef received.

With this network, “superspreader” reefs could be identified. Superspreader reefs were described as those that have lots of connections to different reefs, and can, thus, cause COTS epidemics.

What they found: The superspreader reefs identified in the model matched the reefs that had been historically known for COTS outbreaks – the reefs at Cooktown-Cairns and Swains region.

Basically, the reefs that have the greatest potential to spread COTS and cause COTS epidemics were the reefs  that have had COTS outbreaks in the past.

Omg. The world is ending.

Not yet.

COTS outbreaks can be controlled, but the best solution is prevention. Like Smoky said, only YOU can prevent wildfires, only WE can really prevent COTS outbreaks.

Why this study matters: Only a small, select few of us can do the labor-intensive and expensive process of controlling COTS populations. Rather than treat COTS outbreaks only after they occur, the results of this study identified the superspreader reefs that could be focused. By controlling these reefs before outbreaks occur, other outbreaks can be prevented.

But remember, outbreaks can be a good thing. So our control of these hotspots can also mean allowing outbreaks to develop. But this way we can manage the extent.

Live Short and Prosper

Paper: Uusi‐Heikkilä, S., Whiteley, A. R., Kuparinen, A., Matsumura, S., Venturelli, P. A., Wolter, C., … & Arlinghaus, R. (2015). The evolutionary legacy of size‐selective harvesting extends from genes to populations. Evolutionary Applications.

The title of this post will make more sense once you read about r-strategists.

Raise your hand if you like seafood!

hand raise

Same.

Being land-locked most of the year in PA, I don’t usually eat fresh seafood or any seafood for that matter. But in some places in the world, seafood is people’s primary source of protein.

fish japan

Here’s a map of countries where fish is a major source of protein.

protein consumption fishFish is delish, but like everything else on this planet, fish is a limited resource.

While it seems like we have an infinite amount of fish, like Krabby Pattys…

krabby patty squidawardwe don’t.

overfishing-infograph

Sucks, right?

bummed

We are overfishing the seas. This means that we are taking so many fish out of the ocean that the fish that are left can’t make enough baby fish to replace the ones that were caught.

Not only are we taking a ton of fish out of the sea, but we’re taking the big ones.

big fish japan

No one wants to eat a fish that barely has any meat on it.

By taking too many of the big fish, we’re left with more of the little guys. And since the little guys aren’t caught as much, there are more of them left to make baby fish than the big ones.

That’s like if all of the tall people on Earth were abducted by aliens and only short people were left on the planet to reproduce, the average humans in the next generations would be much shorter.

Aliens haven’t started doing that…yet, but we’ve definitely started doing that to fish.

1970 tuna

Because only smaller tuna are left in the sea to reproduce, the average size of tuna has decreased dramatically. In the 1970s, the average tuna caught weight 1200lbs. Today, the average tuna weighs 600lbs.

tuna 600lb

From an evolution standpoint,

charles-darwin-adapt-or-bitches-funny-picture-18775(I didn’t create this image)

it is likely that the tuna remaining may have also started investing reproductive energy into giving birth to smaller tuna but in higher quantities.

For those unfamiliar with energy allocation and evolution – I’ll try to explain the best way I can. Scroll down to “The Study”  if you already understand this ish.

From a biological standpoint, “success” is spreading the maximum amount of one’s genes to the next generation.  Like genetic world domination.

world domination caroon

This biological goal pertains to everything from fungi to beluga whales to humas (but we’re a little more complex) .

There are two ways to pass on the most genes to the next generation*:

1. make a lot of babies

2. make really badass (big and strong to fight predators and obtain the most food) babies.

(very oversimplified, considered “theories”)*

both downeyIt is too much to ask for both.

The limiting factor is: ENERGY

sims energy needs

Energy – either from food or the sun (if you’re a plant) – powers life.

Reproduction requires energy. There are two overarching reproductive strategies of energy investment:

r-strategists: .

They make a lot of energetically “cheap” babies. They invest their energy into number of offspring instead of size of offspring. They opt for buying a 14 pack of disposable razors instead of going for the single, durable electric razor.

Some examples of r-strategists are flies, bacteria, mice, and barnacles.

mice babies

The advantage: these organisms have more babies to pass on their genes

The disadvantage: the babies are less likely to survive long-term because they are relatively smaller and, essentially, weaker.

The likelihood of mortality is high, but the numbers are high to buffer that.

So if you start with ten baby mice all named Jerry and half of them die by actually getting eaten by Tom, you’re still left with five mice to reproduce and pass on genes.

tom and jerry

Side notes: Because these guys make smaller, “weaker” babies, they tend to have shorter lifespans and reproduce at an early age compared to K-strategists.

Where the title of this post comes into play: Species that follow this reproductive strategy, live short lives, but they prosper.

K-strategists:

These guys make energetically expensive babies, but in fewer quantities than r-strategists. You could say these organisms are most successful by taking the “quality over quantity” approach.

Some examples of K-strategists include: humans, whales, and elephants.

narwhal k strategist(I really like narwhals)

The advantage: these babies are relatively strong and can survive pretty long

The disadvantage: fewer babies means fewer reproductively active individuals to carry out one’s genes.

While K-strategists don’t have a lot of offspring, offspring mortality is low. So even though you may only have two kids, there’s a pretty good chance both will survive long enough to reproduce.

Side notes: Because K-strategists have stronger babies, they tend to have longer lifespans and reproduce later in life. – they live long and prosper.

Most organisms fall somewhere in between r-strategists and K-strategist. Try to think of r/K strategies as a spectrum.

spectrum

For instance, let’s say blue = K strategists and red = r-strategists.

Humans would be in the blue, dogs would be more like a violet-red, and mice would be in the crimson red of the spectrum.

Dogs have more offspring than us (humans) and their babies are smaller than ours, but a dog’s offspring are fewer and larger than rat offspring. So they aren’t really distinctly K or r-strategists. Few animals fall distinctly into r or K.

How does this all relate to fish and the study??

The Study

well we're waiting

I know. I took a long, long time to set this study up, but think of how smart you is now. How much life makes sense! Why whale sharks are so rare and shrimp are so abundant!

awesome chris pratt

Back to the study!

So this experiment looked at whether the reproductive strategy of zebrafish was affected by intense overharvesting of the big guys.

zebrafish

Hypothesis: By removing larger zebrafish from the zebrafish population through size-selective harvesting, the remaining zebrafish population would start reproducing smaller offspring in larger numbers at an earlier age –> exhibit a reproductive strategy closer to the r-strategists.

The Experiment:

(Tbh, not gonna get into the details. You’ve endured enough.)

Breed the zebrafish over five generations, removing the larger individuals each generation to mimic a typical harvesting season by humans in the wild.

Then, measure the average size of the zebrafish and analyze their DNA to see if a shift in reproductive strategy occurred at the genetic level.*

(I realize I oversimplified this concept, but I just want to get the message across)

DNA gif

A decrease in the average size could just be a surface (phenotypic/what we see) change. When I originally explained size selection, I mentioned how the average size of tuna could be smaller simply because there are smaller tuna in the sea left to reproduce.

However, a genetic analysis shows whether or not the fish are “intentionally” (for lack of a better word) smaller.

Aka, the scientists wanted to determine whether the youngest generation of fish are now genetically coded to produce smaller fish at earlier times and in larger numbers than the original generation of fish.

Genetic changes like this take a llllllooooooooonnnnnnnnnngggggggg time.

watch clock

Because genetic changes like this can only accumulate over generations.

–But that’s another story. (I’m no storyteller. I pee greatness like gold is yellow. – name the song for $10) And I’ll save that for another day. —

In order for genetic change to accumulate and persist in the genetic code of the zebrafish population in this study, the zebrafish were bred (and big guys were removed) over five generations.

four generations

Only four generations of humans are pictured above, but we generally don’t live long enough to see more than three generations.

Results:

Of the fish in the fifth generation….

– The average adult body size at reproductive maturity decreased

– Genetic evidence confirmed that the fish invested more energy into reproduction than into body growth (hence, they were a smaller size and younger when they became sexually active)

– Because of their smaller size (and resulting reduced strength and dominance), the fish were less bold and explorative. They became scaredy cats -they had to be careful not to become somebody’s dinner.

shy pug

This pug isn’t afraid of anything eating it. It’s just shy.

Moral of the Story:

Harvesting the larger fish of a species’ population over generations can cause the fish species to reproduce more, smaller fish.

More fish! That’s good, right?

dwight-schrute-falseMore fish is great in the sense that the species is less likely to go extinct, but these fish are smaller fish.

They have less meat.

You’ll order fish and be like…

feed me more

Ordering a pound of fish could mean combining the meat of multiple fish to reach one pound.

Which changes the quality of the meat.

jack sparrow gross

The solution:

There are several angles to take.

– purchasing and ordering seafood from a certified sustainable fishery

these can bear the following logo on their packaging:

marine stewardship council logo

– following Monterey Bay Aquarium’s Seafood Watch Guide

– abstain from eating fish (the most sustainable choice, at least as far as my understanding lies)

As much as I love seafood, I am trying to eat only invasive species (ex: lionfish – another story for another post) because I am not certain truly “sustainably fished” seafood exists.

But seafood is an important source of protein to a significant portion of the world’s diet. And at least by following the guidelines in the Seafood Watch Guide or paying attention to what fishery one’s seafood comes from, the impacts of overfishing can be mitigated.

seafood watch guide logo

seafood watch guide

Thank you for taking the time to read this post. I spent a lot of time on it because I felt its contents were interesting and important, but that’s just my opinion. Let me know what you think!

Take a Deep Breath…Literally

Paper: Deutsch, C., Ferrel, A., Seibel, B., Pörtner, H. O., & Huey, R. B. (2015). Climate change tightens a metabolic constraint on marine habitats. Science,348(6239), 1132-1135.

Wooooowee is it hot out lately.

Every time I go outside…

boob sweat

But…

boob sweat whole time gif

This hot weather is not only bad for Chris Pratt’s and my boob sweat (he could rock boob sweat anyway), but also terrible for breathing in the sea. Let me explain.

Aquatic life needs more than just water to live.

spongebob need water

They also need air. And by air, I mean oxygen.

But how do they get air? They live underwater. If there was air down there, couldn’t we live there, too?

confused bale

As you probably already know, but I’m gonna say it anyway, fish don’t actually breathe water.

Fish and other aquatic life breathe the little bits of oxygen that dissolved in the water, referred to as “dissolved oxygen,” DO.

You don’t need to read this whole diagram, but I just wanted to show what that means, kinda.
dissolved oxygenBasically, oxygen from the atmosphere mixes into the surface waters of the sea and critters can bring this oxygen.

Colder water can dissolve more oxygen than warmer water. But there’s enough oxygen – at present – in tropical waters for the sea life there to breathe.

under the sea bubble

Just look at all of those bubbles.

Anywho, the researchers of this week’s paper looked at how the reduction of dissolved oxygen in the sea (due to warming temperatures via climate change and overall loss of O2) will impact where different organisms can live based on their oxygen demands.

This was a pretty math-based paper, but don’t worry. We’ll get through this together.

leo hold hand(Leo is not only beautiful, he is also super passionate about the environment. Leonardo DiCaprio Foundation)

The scientists figured out how much oxygen each species they studied needed for their resting metabolism. Aka how much oxygen they breathe just exist.

lazzzy

Like this guy.

Obviously, these animals do more than watch cartoons all day and need more oxygen to catch dinner, avoid predators, and make babies.

Here’s where math starts to come into play.

The scientists defined “metabolic index” as the ratio of the amount of oxygen available in the environment, the supply, to the amount of oxygen the organism needs for its resting metabolism.

If this ratio is equal to 1: the animal can do no more than watch Netflix all day and just breathe

If this ratio is more than 1: the animal can hit the gym and catch tonight’s dinner and do lots of stuff

room for activities

If this ratio is less than 1: the animal can’t even breathe and must do anaerobic respiration (aka breathing without oxygen) which they can’t do for very long before dying. they basically suffocate

The ratio across the globe did not vary much seasonally or longitudinally, but did vary a bit with latitude. Also, the ratio didn’t increase significantly in deeper water.

In the low-latitude tropical water, the ratios were pretty low:

1. there’s less oxygen in tropical water since it’s warmer there

2. organisms in warm environments have higher metabolic rates – aka need more oxygen for their resting metabolism

The tropical seas suffocate in their own beauty.

tropicss

Meanwhile, closer to the poles, the ratio was much higher because the water holds more oxygen since the water temperature is colder and organisms there have lower metabolic rates.

arctic ocean gif

As the average sea temperature increases due to climate change, the amount of oxygen in the water will decrease.

So the ratio of habitats close to the equator will decrease. For some critters, this means their ratio (oxygen supply:demand) in these locations could drop below 1 and they won’t be able to live there anymore.

snookie need to go

Breathing issues, that is.

This study looked at how the ocean temperature projected for the end of the century – a bit warmer than today’s – will affect where certain species can live based on metabolic index ratios.

The animals examined spanned a variety of habitats.

Mid-latitude open ocean: Atlantic Cod

cod

Mid-latitude benthic (bottom-dwelling): Atlantic Rock Crab

atlantic rock crab

Subtropical latitude: Seabream

sea-bream

Subpolar latitude: Common Eelpouteelpout

V cute.

What they found:

In 100 years:

– cods will have to dive deeper in the summer to escape the warmed surface waters — they will have to take deep breaths – get it? breaths at deeper depths. The title of this post!

I’m so funny.

funny tyson

– rock crabs will have to move roughly 10 deg latitude north for more oxygen

– depth zones of organisms will shrink

– habitable zone of organisms will move toward the poles

However, not all of this will happen for sure.

mickey mouse unsure

Many factors affect how much oxygen is in the water.

Primary production (algae growth, etc) will affect the concentration of oxygen in the water. Algae and plants of the sea produce oxygen. When they die, they’re eaten by bacteria who use oxygen. So this relationship of primary production and oxygen concentration is a bit complicated.

algae

The acidity of the ocean, which is projected to increase, could also affect dissolved oxygen concentrations. Additionally, pollution can impact oxygen levels.

From a biological perspective, some of these organisms will be able to adapt or the species could evolve over many generations to decreasing oxygen conditions. But that often takes many, many years depending on the species generation time and is unlikely to keep most organisms’ habitable range the same.

slow sloth

The only thing we do know for certain is that increasing temperatures have a negative impact on oxygen supply for organisms. So we should do our best to reduce our release of GHGs (green house gases – like carbon dioxide) and slow the warming of the seas!

high fivee

Words from the Left Shark

Paper: O’Connell, C. P., Hyun, S. Y., Gruber, S. H., & He, P. (2015). Effects of barium-ferrite permanent magnets on great hammerhead shark Sphyrna mokarran behavior and implications for future conservation technologies.Endangered Species Research, 26(3), 243-256.

Left shark from Katy Perry’s Super Bowl show actually did not write this. But I bet he would if he had opposable thumbs.

In light of the recent shark encounters off the coast of North Carolina, this week’s article is about sharks.

I just want to remind you that as flawle$$ and delicious as you think you are…

flawless

sharks don’t actually want to eat you.

gross food

I hate to break it to you, but you are not nearly as tasty as a sea lion or other fish.

tasty seal

Look at that tasty, little seal. Yum.

While it has been widely known that humans are not on a shark’s menu, humans have been a part of some shark defensive and feeding behavior.

shark attack news

But like I said, this behavior is NOT specifically directed at humans.

I’m not saying it’s totally fine that those poor kids were severely injured, but I am saying that their injuries are no reason to start killing shark sprees because of this – like how the Jaws film generated that mentality and wiped out so many innocent.

shark killings

((Really made me sad to Google pictures of this))

I totally agree that sharks are wild animals capable of harming humans. So we should be smart about swimming in their home, the ocean. Some measures have been taken to separate sharks from humans, such as nets.

shark net

However, more than just repelling sharks, these nets actually result in many shark and other animal deaths.

turtle in net

shark in net

Speaking of hammerhead sharks, this paper specifically looked at hammerhead shark deaths by nets and experimented with an alternative to shark nets.

In a span of less than 20 years, about 1300 hammerheads died via shark nets in New South Wales, Australia. In South African waters, over a period of 15 years, roughly 3400 hammerheads died in shark nets.

Not cool.

angry coachSeriously.

So the scientists of this study decided to investigate the potential of utilizing the electrosensory capabilities of hammerhead sharks to devise a more eco-friendly shark repellent.

(Animal behavioral studies is a field very foreign to me so bear with me.)

The plan: use magnets as a shark repellent

Magnets can sustain their own field without an outside energy source, and they don’t capture sea turtles or other cuties like nets do. Such a sustainable solution. But wait.

I thought these sharks had electrosensors, not magnetosensors?

Here’s where your old best pal Faraday from physics class, who you used to think was…

irrelevant

is relevant!!!

When a shark goes through a magnetic field horizontally, an electromotive force is induced – according to Faraday’s Law. If a shark is swimming at 1 m/s, the shark can induce a voltage gradient at its receptors up to 25 uV/m (micro-volts per meter) – which is a much higher voltage than the minimum for shark detection.

If none of that sounded like English, basically (in a v brief sense), sharks can sense a magnetic stimulus indirectly by the magnetic induction of an electrical stimulus.

Now that we’ve got the physics taken care of…

yayyy

we can move on to the experiment.

The study tested the effects of the magnetic field generated by a barium-ferrite (BaFe12O19) magnet on the behavior of the great hammerhead shark, Spyhrna mokarran, in two experiments:

Bait experiment

Barrier experiment

In each experiment there was a control (C), procedural control (PC), and a magnet (M).

While one experiment was specifically called “Bait experiment,” bait was used in both experiments to lure in sharks to the site.

This bait was none other than the most delectable, great barracuda.

Great Barracuda (Sphyraena barracuda) Bonaire

Wow. My mouth is currently watering. How could any shark resist? In fact, how could any creature resist? I’ll tell you how. The barracuda bait was placed in a mesh bag so no other fishies could remove the bait.

The (Great) (De)Bait Experiment

In this experiment, each condition (C, PC, M) involved a PVC pipe. In the control, there was nothing but bait inside the pipe. In the PC, there was bait and a clay brick – serving to look identical to the M pipe. In the M, there was bait and the magnet. The brick and magnet were covered in black duct tape to make them visually identical. The pipes were placed over 1m apart randomly to eliminate side preference of the shark.

Here’s what it looked like:

figure 1 ocennell sharkThe shark behaviors recorded were: visits, avoidances, feedings, and no reactions

Visits = shark swam within the observation zone

Avoidances = a visit followed be a sharp turn/acceleration away from the zone

Feedings = when a shark ate the food, duh.

No Reactions = when a shark did none of the above

The number of sharks present and number of sharks of the same species and different species were recorded for conspecific (same species) and heterospecific (different species) densities. Since sharks are presumed to be competitive, it was hypothesized that the presence of competitors would make them more likely to feed even though their electroreceptors didn’t agree.

Also, the scientists recorded repeaters, same shark at site more than once. These sharks were subsequently labeled Lizzie McGuires.

outfit repeater giff

jk

The Barrier Experiment

In this experiment, a rope with some buoys spaced along were placed in the observation zones. In the control, the buoys had nothing attached. In the PC, the buoys had little bricks spaced out along ropes hanging vertically beneath each buoy with one giant brick on each to hold each rope vertically. In the M, the buoys had little magnets spaced out along the ropes hanging vertically beneath each buoy and one giant magnet on each to hold each rope vertically.

Here’s what it looked like.

barrier experiment sharkkksThe behaviors recorded in this experiment included: visits, avoidances, entrances, pass arounds, and no reactions

New behaviors definitions:

Entrances: visiting observation zone and swimming through the PVC

Pass Arounds: visiting observation zone and swimming parallel to PVC rope barrier but not swimming through or avoiding it

Data collection and statistics

The trials took place over two years and occurred during daylight. In the barrier experiment, the barrier containing the magnet was switched with a different treatment’s spot each trial to increase randomization. Each trial lasted 30 minutes.

While this took place over two years, the experiment was carried out on 19 days for the bait experiment and 17 days for the barrier experiment, which resulted in 90 trials of the bait experiment and 42 trials of the barrier experiment.

The data were run through various statistical tests to come up with a model that coordinated all of the variables signficantly. If you took STAT 462 Applied Regression with Steph, you could follow like two paragraphs of the Results section.

But the results section was longer than two paragraphs, and I got a little lost.

Like Alice.

alice in wonderlad

But the experience was much less magical. I don’t recommend it for the non-stat oriented.

Here’s the bare bones of what they found:

Bait experiment:

Avoidances: C=0, PC=1, M=21 – there were statistically significantly more avoidances recorded of the magnet pipe than the other treatments.

Feeding: using fancy statistics, the scientists found there was a negative correlation with feeding frequency and presence of magnet. aka feeding frequencies decreased with presence of magnet

Barrier experiment:

Avoidances: the best fitting model the scientists generated showed that the presence of the magent was significantly correlated with avoidance frequency

Entrances: Entrance frequency decreased in the presence of both the procedural control bricks and the magnet. However, the magnet had the bigger impact on decreasing entrance frequency.

Pass arounds: Magnet presence was a significant predictor of pass around frequency. The presence of the magnet actually increased pass arounds – which likely means that the shark could detect the magnet – it stayed near the barrier but did not pass through it.

Both experiments:

Heterospecific/conspecific densities: when other species were around, entrance frequencies increased, but other than shark behavior was not really altered by more of its own species or other guys. It did what it wants.

i do what i want

So will magnets be used as shark repellents now or not??

More research needs to be conducted. The most likely situation would be that these magnets are dispersed along the entire depth of the water column so bottom-dwelling and surface-dwelling sharks are both deterred.

Another issue is habituation. Which basically means that a subject stops responding to stimulus after prolonged exposure. In other words, the shark could get used to the magnetic stimulus over time and begin to ignore it. If the magnets are moved around frequently enough the field will differ prolonging time to habituation.

For now, we will live with the shark nets, but many other sea creatures won’t.

If you take anything away from this post, please remember that sharks just want to live their life – even if we get in the way sometimes. One day, we will live in sustainable harmony with both left and right sharks.

left or right shark

Invader Sym…biodinium trenchii

Paper: Pettay, D. T., Wham, D. C., Smith, R. T., Iglesias-Prieto, R., & LaJeunesse, T. C. (2015). Microbial invasion of the Caribbean by an Indo-Pacific coral zooxanthella. Proceedings of the National Academy of Sciences, 201502283.

Invader_Zim_Operation_Doom_cover

Believe it or not, this paper does not discuss early 00’s cartoons. But it does discuss invasions and possible doom.

sardines spongebob

Similar to the invasion of anchovies during the first episode of Spongebob ever, the invaders of this study are also quite hungry.

However, this invader is much smaller.

Invader: Symbiodinium trenchii 

Symbiodinium

Symbiodinium trenchii is an endosymbiotic dinoflagellate – unicellular algae – that resides in many coral species and gives the coral nourishment in exchange for a home. It’s more complicated than that, but that’s the gist.

nodding

To understand this study, I’m gonna break down coral physiology a lil bit.

break it down

Corals are animals. They are a colonies of tiny polyps, which filterfeed itty bitty food floating around in the water. For big reef-building coral species (hard corals or scleractinian corals), those little bits of food usually aren’t enough to keep the coral full and happy.

oliver

The coral just want some more, sir. They get more food by letting that unicellular algae, Symbiodinium, live in their skin. The Symbiodinium – often called zooxanthella – produces extra photosynthates – or sugars from photosnythesis – that the coral can gobble up as they please.

Also, the color of the zooxanthella in the coral gives the coral its color.

coral anatomy
This diagram shows the coral polyps as the medusa looking things with zooxanthellae within the polyp. The hard coral’s calcium carbonate skeleton, “CaCO3 skeleton,” is also shown, hanging out underneath the coral polyps.

This skeleton is what gives hard coral their name. Hard coral deposit a skeleton and grow over it.

(See Dropping Acid for a better explanation)

Back to the paper:

Different species or types of zooxanthellae can reside in coral, such as Symbiodinium glynni and Symbiodinium trenchii.

Classifying these species and strains can get complicated. I don’t really understand it fully tbh, but what you need to know to understand this study is that different types of zooxanthellae can live in coral and that these zooxanthellae give the coral food via photosynthesis.

So this study looked at which Symbiodinium were living in the Indo-Pacific vs. the Caribbean.

indo-pacific-map

vs.

Caribbean map

The sampling from the Indo-Pacific was at two locations: Adaman Sea (eastern Indian Ocean) and Palau (western Pacific Ocean).

Sampling from the Caribbean was very widespread: Barbados, Belize, Curaçao, Florida Keys, Flower Garden Banks, Mexico, Panama and St. Croix.

Here’s a better pic of the sampling:

sampling location pettay paperThis is Figure 1 from the paper. We’re just gonna focus on the map parts of this figure for now. The Indo-Pacific coral sampling locations are shown together in A, and zoomed in is B and C. B is the Adaman Sea and C is Palau. D shows the Caribbean sampling locations.

((structuring the rest of this like the paper bc I really like the way the paper was organized))

Symbiodinium diversity in the Indo-Pacific:

While the two sampling sites in the Indo-Pacific were far apart, the coral colonies sampled at each site were pretty close together, sometimes only 10km apart. Even at these small distances, the diversity of Symbiodinium was super high.

If you look back at figure 1, the black portions on the bar-graphs at B and C represent unique genotypes of Symbiodinium found there. (Genotypes describe the genetic makeup of an individual – I won’t get into specifics of this paper, but basically like we’re all humans but all different genotypes, the Symbiodinium found there were mainly all different genotypes.) Few coral had the same genotype of Symbiodinium in their tissue. The colored regions on the bar correspond to the same genotype. In the Indo-Pacific bar graphs, you can see there are only a couple short colored portions.

Basically: The Pacific had high diversity of Symbiodinium even over short distances between coral colonies.

As for the Caribbean:

The sites spanned widespread distances, and the coral colonies sampled at each site were up to hundreds of km apart. However, clones, same genotypes, of Symbiodinium, resided in coral even thousands of km apart. The most common genotype of Symbiodinium is represented in the red colored block, which was found frequently at all locations. The unique genotypes, represented in black, is a very small portion of the bar graphs compared to the Indo-Pacific graph.

In short: The coral sampled over much further distances in the Caribbean often had Symbiodinium of the same genotype, aka low Symbiodinium diversity.

On top of that, none of the genotypes found were unique to the Caribbean. The genotypes were all also found in the Indo-Pacific. In contrast, the Indo-Pacific had a ton of genotypes that were only in the Indo-Pacific and not in the Caribbean. Figure 2B from the paper shows a gene tree of all the genotypes uncovered in the study.

genotypes symbiodinumThe little red group in B shows the Symbiodinium genotypes found in the Caribbean/Atlantic, the orange = Indian Ocean and blue = Pacific Ocean. As you can see, the Caribbean genotype varieties are much fewer and clustered together compared to the other regions’ genotypes, spanning the length of the graph.

In C of figure 2, the distribution of genotype diversity observed was compared to the expected diversity of the region. The expected diversity is shown in white and has a bell-curve shape. The observed diversity is in dark gray and the overlap between expected and observed is in light gray. In the Atlantic, you can see the observed is greatly skewed right – suggesting much lower diversity than expected, where as the Indian and Pacific genotype diversity graphs almost match the expected diversity curve.

Basically: There is significantly less Symbiodinium diversity in the Atlantic/Caribbean than in the Indo-Pacific.

The most common genotype of Symbiodinium found in the Atlantic was a variation of Symbiodinium trenchii.

What’s so special about Symbiodinium trenchii?? Why does it dominate?

feeling special

When coral bleach – lose their symbiotic algae Symbiodinium – because of warm temperatures or other stressors, they can either recover (get a symbiotic algae back) or die.

Certain Symbiodinium are better adapted to hot temperatures, unlike poor Goofy.

hot

So these Symbiodinium are more likely to colonize the coral tissue before the zooxanthellae that can’t handle the heat as well have the opportunity.

Symbiodinium trenchii is one of those guys that can handle the heat.

heat fire

Not quite that hot, but warmer temps than other Symbiodinium.

This study then looked at how well this S. trenchii performs in the coral species, Orbicella faveolata.

orbicella faveolata up close

o. faveolata symbiodinium(figure 3A from the paper)

((This is the first species of coral I’ve ever worked with *nostalgia*))

The O. faveolata colonies this study looked at originally had the Symbiodinium types: A3, B17, C7 (like I said, don’t ask me how they classified them)

They looked photosynthetic rates when the O. faveolata colonies had their usual symbiont in them and compared that to when these colonies had S. trenchii. based on oxygen evolution (see the paper’s supporting info for what oxygen evolution is – I don’t fully understand).

symbiodinium ps rates up close

As you can see in Figure 3B from the paper, the maximum rate of photosynthesis (Pmax) with the different symbionts in the coral was not much different when S. trenchii was in the coral colonies.

Aka, S. trenchii produces relatively the same amount of photosynthates when living in the coral which it is not originally adapated to live in.

HOWEVER, the coral did not calcify (make their calcium carbonate skeleton) as much as when S. trenchii was in the coral compared to when their original symbiont was in them at high temperatures.

symbiodinium calcification rates pettay

Figure 3C shows the calcification rates of the coral at different temperatures when the different symbionts were in the coral. Red = S. trenchii, Yellow Green and Blue = the other symbionts.

When temperatures reached like 28 deg C, the coral with S. trenchii started depositing significantly less skeleton than the coral did with their original symbionts.

What does this mean??

question excellent

S. trenchii is an opportunist microbe that colonizes coral during times of high stress, like high temperatures. While it can photosynthesize the same amount in the O. faveolata as other symbionts, S. trenchii keeps more of those photosynthates for itself, rather than giving more to the coral. Like I said earlier, it’s a hungry invader.

Because S. trenchii keeps more of the photosynthates, its host coral calcifies less. If the coral cannot produce a strong enough skeleton, the coral is more likely to break a leg. Except coral don’t have legs, so they just break into pieces, unlike this cute puppy.

broken leg

The advantage of S. trenchii and why it is so dominant in the Caribbean/Atlantic is that temperatures are increasing in the Atlantic as the world warms due to climate change. With the water being warmer, coral are more likely to bleach more frequently and for longer periods of time. Since S. trenchii can handle higher temperatures, it is more likely to colonize bleached coral before the coral’s original or similar symbiont can recolonize.

The plus side of S. trenchii‘s existence is that if temperatures are too high for too long and that the coral is likely to die, S. trenchii can slide in and give the coral some food.

But not enough food. S. trenchii could be problematic if the coral aren’t able to produce enough skeleton to grow big and strong.

strong

I’m not gonna get into the detailed genetic explanation, but because Symbiodinium trenchii is a genotype found a little bit in the Indo-Pacific, but clonal and widespread in the Atlantic, it is likely that S. trenchii was introduced to the Atlantic via ballast water of ships coming through the Panama Canal. And then S. trenchii took over coral in the Atlantic during bleaching events.

So you could say Atlantic/Caribbean coral experienced an invasion of S. trenchii like the musical world experienced in the 60’s.

british invasion

Except the invasion of S. trenchii is not a good thing and doesn’t involve British bands. S. trenchii‘s invasion gives it merit to be deemed an invasive species for several reasons:

– opportunistic, widespread colonization in the Atlantic

– host generalist – can colonized a bunch of different species of coral

– negatively impacts coral growth

More studies need to be done to completely confirm all of the above, but this study showed pretty compelling evidence that S. trenchii could star in the next kids cartoon called Invader Sym.

East Coastin’

The last few weeks have been a whirlwind, but my weekly posts are finally returning for the summer!!

happy dance gif

I know, I’m so excited too. ((I also do not know who that man is, but I am really channeling him right now))

What’s been going on? What could I have possibly been up to for the past month?

lazy gif

…I wish I had been that stranger above! I did get to decompress a bit after finals, but never to that point.

I started my internship at Harbor Branch Oceanographic Institute in Fort Pierce, FL this past Tuesday.

hboi campus

The building I work in is covered in trees.Of course.

Fort Pierce is on the Atlantic coast of FL. Last summer, I was along the Gulf side. I can’t tell which side I like better. The water of the Gulf was super warm – which I like – but had no waves. The water of the East Coast has waves, but isn’t super warm. A final verdict will be made at the end of the summer. Stay tuned.

I’m living in an apartment on-site – like a seven minute walk away – so no excuse of bad traffic for being late.

Back to science!

scienceee

Yes, I am, in fact, working with coral again this summer.

The species: Montastraea cavernosa ((and potentially Pseudodiploria clivosa))

M. cavernosa is the only Montastraea coral left in the genus after the re-classification of many Montastraea coral to Orbicella.

montastraea_cavernosa_day_b

The experiment: analyzing the shift in composition of the bacterial communities of M. cavernosa mucus before and after exposure to freshwater discharge water

Basically, coral have a mucus layer on the outside of their tissue.

Coral-Mucus-Figure-2_326253

The yicky, white, cloudy stuff is the mucus. But it usually doesn’t shed like that. It just chills on top of coral at all times. So you don’t really even see it.

Some of the bacteria in this mucus have been found to help coral acquire nutrients (like the coral’s photosynthetic algal symbiont Symbiodinium) and other bacteria have been found to produce antibiotic compounds to prevent pathogenic bacteria from colonizing the coral and causing disease.

Black_Band_Disease f

In this picture, the disease is that black strip which kills the coral as it grows along. The dead part of the coral is the white part, which can then get colonized by algae and other stuff – the fluffy stuff in this pic.

Anyway, back to my project.

So I’m seeing if freshwater discharge has an effect of what types of bacteria are chilling in the mucus.

What do I mean by freshwater discharge?

discharggge

The dark water is the freshwater, the lighter water is the ocean water.

How does this much freshwater get to the sea so fresh? It’s not discharge from a river.

The water comes from Lake Okechobee – which is decently far inland. So how does its water get to the coast?

Way back when, the dam system for Lake Okechobee could have used repairs, but nobody did anything about it. Eventually, the water level of the lake began to overflow.

To direct the freshwater from flooding everywhere, a canal system was built.

lake okechobee canals

My labmates have a better map of the canals, but this picture shows the St. Lucie Estuary Drainage Canal, which is the source of the discharge water that affect the coral in my project.

These canals used to release freshwater the entire FL rainy season. However, now they only open and shut as needed.

I will be looking at the mucus of M. cavernosa right before the canals were opened in June of 2014 and after the canals have been opened for two months – in August 2014.

How will I characterize the composition of the mucus?

DNA double helix with ACGT and binary numbers in the background.

NEXT GENERATION SEQUENCING

Put simply, I will be looking at which bacteria are present based on DNA sequences. If one of the DNA sequences from the mucus matches a known bacterial species, then this bacteria is present.

Simpler, cheaper methods of sequencing enable you to classify a sample at Phyla level.

classification chart

But, as you can see, this analysis isn’t very specific. If only a few species are expected to be different for my project, I need much more specific analysis of the mucus.

Which leads us to NEXT GENERATION SEQUENCING.

Next Generation Sequencing – I will call next-gen for short – is kinda complicated for me to explain here. But basically, it will figure out which bacteria are present based on reads of sample DNA. Sometimes you only needs a few thousand reads of the DNA to identify all of the species present in your sample, but sometimes you need like 500,000.

The more diverse you expect your sample to be, the more reads you need to catch every species – which may only be present at 1%.

No one has ever performed next-gen sequencing on the bacterial community of coral mucus ever – let alone that of M. cavernosa‘s mucus. Every species of coral’s mucus is different.

Thus, I have to figure out how many reads I will need based on literature search and educated guessing.

The challenges with educated guessing are:

1. The samples will need to be sent to a facility and the sequence data can take many weeks to get back. I might not have any data by the end of my internship. =[ This isn’t a huge deal because I could analyze the data at Penn State when I get back, but it would be nice to have the data to present and write my paper for the internship.

2. Next-generation sequencing is super-duper expensive. We really wouldn’t want to have to do this twice if I picked a number of reads that was too low.

moneyy

aka I have ONE shot at picking the number of reads.

*cue “Lose Yourself” by Eminem

one shot eminem

Why not just pick a really high number of reads – like a million reads – to ensure all the diversity is detected? It is expensive.

I will also be performing LHC-PCR, which is less specific than next-gen, but if these data show differences in the communities, we can get a better idea of number of reads we will need.

So I’ll have the LHC-PCR data to work with if next-gen takes too long.

But this will be me once I get the next-gen data:

next generation sequencing cartoon

Wish me luck. My mentor had described me as “one of those students with an incredibly, overly ambitious project.” Why didn’t he stop me????

Well, here goes nothing!