Fish

by Erin Loury, Ichthyology Lab

There’s nothing like seeing the food-chain in action to make you appreciate how important eating is in an animal’s life – and why it’s so important to study (says the fish guts girl)!  For many things in the ocean, it’s just a matter of time before they become something else’s lunch.   It’s a fish eat fish world out there!

This week’s photo comes from summer surveys I participated in with the California Collaborative Fisheries Research Program while we surveyed new marine protected areas in central California.  The photo is of a lingcod, and shows off the feature that is probably most important to appreciate when working with these fish – TEETH!  Those are a clear indication that this fish is a predator, and it means business!

What you see in its mouth is the tail end of a hapless rockfish experiencing the ultimate “game over.”  This particular lingcod ate the rockfish right out of the fish trap that both were caught in, but are also big predators on rockfish in the wild too.

Chances are you’ve probably eaten rockfish or lingcod yourself if you live in California – meaning this photo really shows three levels of the food chain – rockfish, lingcod, and humans.   Humans are probably the most voracious predators of all in the marine environment, emphasizing the need to appreciate what we eat, and what it eats in turn!   So the next time you get that fish taco or fish and chips, think about how you are taking part in the bigger ocean food chain.

by Erin Loury Ichthyology Lab

No, this isn’t an elaborate fish puppet you’re looking at – it’s a Giant Grenadier caught in the depths of Monterey Bay on a research cruise.   If it looks a little worse for wear (that pink color is from all its scales falling off), it’s because the fish was pulled up from a depth of around 1,000 feet.  Like most deepsea fishes, the different species of grenadier tend to grow slowly, reproduce late in life, and can live to be quite old (several decades) – all of which makes them susceptible to overfishing.

Yes, believe it or not, fishing is a real issue for these squishy critters.  Grenadier now makes an appearance on the West Coast version of Monterey Bay Aquarium’s new 2010 Seafood Watch pocket guides.   And they’re in the red – that’s the “Avoid” section.  In addition to a slow-growing life history, the fishery for grenadier is virtually unregulated, and often the result of destructive deepsea trawling.  This is all good news you can use  – I recently saw grenadier on a menu for the first time.  Now I know to steer clear.

Curtailing demand for this fish probably wouldn’t be a problem if people only knew what it looked like – besides, how appetizing is something also called a “rattail”?

Thanks for the photo, Mariah!

by Kristen Green, Ichthyology Lab

September 2009: For the next three weeks, I am traveling to Cocos Island and the Las Gemelas Seamounts, which are located approximately 520 kilometers southwest of Costa Rica. Cocos Island is renowned for its marine biodiversity, and the island has been established as both a UNESCO World Heritage Site, and as a National Park in Costa Rica.

I will be working with scientists from the US National Geographic Society, University of Costa Rica, Ocean Research & Conservation Association, and the Monterey Bay Aquarium Research Institute to explore deep water habitats via manned submersible around Cocos Island and the nearby Las Gemelas Seamounts.

Manned submersibles are like miniature submarines; they allow scientists travel to ocean depths that would otherwise be inaccessible. We will be using the DeepSee submersible, which has room for a pilot and two passengers, and can travel to a maximum depth of 1,500 feet. We will use the submersible to record video images of the seafloor habitat, fishes, and invertebrates, as well as to collect invertebrate specimens from the seafloor.

In addition to the submersible dive operations, there will be several other research projects conducted during the research cruise. One team of scientists will be using SCUBA to identify and count fishes in shallower waters (less than 80 feet) around Cocos Island. Another team of scientists plan to catch sharks and implant them with sonic tags. These sonic tags transmit signals to receivers, which are like underwater listening devices. These receivers will be stationed all around the island. When a shark with a tag swims in the vicinity of a receiver, signals from the  transmitter will be detected by the receiver. The transmitter signals include information about the animal’s depth and location. These data will help scientists understand where and when the tagged sharks move around the island.

by Mariah Boyle, Ichthyology Lab

Hi, this is Mariah, an ichythyology student here at MLML. I want to let you know that a local non-governmental organization (NGO) I work for, FishWise, is hosting a screening of The End of the Line, an amazing documentary about the global overfishing of our oceans.

This documentary is excellent, as it is based in science – you will hear from leading scientists such as Daniel Pauly and Ray Hilborn in the film. This film also reminds us of the global nature of overfishing the oceans, as what we do here in California affects the rest of the world, and vice versa.

After the film we will have a panel with local NGOs, New Leaf Markets, and H&H Fish to discuss what we can do as individuals and as a community to address overfishing. Please join us as we talk about how to make choices in our lives to help solve the overfishing problem. I hope to see other fish fans there too!

Screening is December 16th (Wed) at the Rio Theatre in Santa Cruz, starting at 6:30pm. Tickets are $3 at the door.

by Erin Loury, Ichthyology Lab

On this, the national day of overeating,  I thought I would kick off our new featured photo segment with an example of a stuffed gullet from the animal world.  For my thesis studying what gopher rockfish eat, I’ve cut open a lot of fish (somewhere in the ballpark of 700, and finally as of this week there are no more fish in my freezer!  Woohoo!).  Every now and again I’ll see something surprising or out of the ordinary – but none so much as this one.

To give you some perspective, most gopher rockfish stomachs that are empty or have a bit a food are the size of my thumb.  The one pictured above was closer to the size of my fist.   I’ll put it this way – their stomach lining is some kind of fantastic elastic.  What floors me is that this little porker was caught with hook and line, meaning after all that eating, it still went for some bait.   But I guess when that pie comes around at the end of tonight, I’ll  probably be able to relate.

Just what kind of food does a gopher rockfish pack in at such staggering volumes?  Stay tuned to find out!

by Erin Loury Ichthyology Lab

The queen of marine creativity stikes again! Diane Haas, an Ichthyology Lab student (who you may know as creator of some sweet, toothy shark cupcakes) crafted this vision in frosting for labmate Tom Wadwsorth’s thesis defense last week.  The lucky subject?  A China rockfish (Sebastes nebulosus).  What a delicious complement to Tom’s thesis, “Trends in Abundance Surveys of Nearshore Rocky Reef Fishes in Central California 1959-2007.”  Congrats, Tom, and two thumbs up to Diane!  (Oh, would this cake qualifiy as sustainable seafood?)

by Mariah Boyle, Ichthyology Lab

At MLML, many graduate students need an outside job to help pay the bills while working towards their degree. My outside job that gives me  a different perspective on the oceans –  I work at FishWise, a non-profit sustainable seafood consultancy in Santa Cruz, that helps seafood producers, distributors, and retailers source and sell more sustainable products. Working with seafood consumers and the seafood industry allows me to apply my background of research in fish science (ichthyology) to the real problems facing our oceans today like contaminants, overfishing, and pollution.

Sure we all think about the oceans when we pick up litter off the beach or don’t pour anything down the street drains that lead to the oceans, but what about when we shop for groceries? It is time we all took responsibility for what seafood we eat, whether in the grocery store or at a nice seafood restaurant.

Now there is a new blog that can help you do just that! FishWise has launched a blog on our website to help consumers think more critically about the seafood they eat.

Take this seafood quiz to learn if you are FishWise!

1.    What is more sustainable, farmed or wild salmon?
2.    True or False: Fish can live to be 100 years old.
3.    True or False: Some catch methods, like bottom trawling, have high amounts of bycatch, even including turtles!

To learn more about the above questions, check out our blog to read the full stories and become FishWise (check the comments section below for the answers).

Want to do even more? Shop at a FishWise member retailer to support stores that source more sustainable seafood. All FishWise member retailer partners label the sustainability of their seafood right on their seafood signs!

Is your local grocery store not FishWise yet? Tell them to go to www.fishwise.org to learn more!

by Erin Loury, Ichthyology Lab

Have you ever stared in the mirror and convinced yourself that your eyes are different sizes? Even if they are, or even if one is a little higher than the other, don’t worry, you are still considered symmetrical. That is, you could draw a line down the middle of your body from head to toe, and your left and right sides would be more or less equal to each other, just mirror images. Most animals share this condition called bilateral symmetry, with left and right mirror images – everything from whales to ants. A few animals like sea urchins and jellyfish have radial symmetry, meaning that you can draw many lines through them to get mirror images (they’re symmetrical in a circular way).

Symmetry is so common than nature that scientists get pretty excited to study any animal that deviates from this norm. A bizarre and fascinating example is the asymmetry of flatfish – fish like halibut, sole, sanddabs, etc. – which can’t be divided into equal right and left sides. Instead, they have two eyes on one side of their head – which isn’t such a bad idea if you make your living with your other side buried in the sand. The crazy thing is that these fish aren’t born that way – they’re born with bilateral symmetry just like most other fish!

On our ichthyology class cruise last week, we pulled up examples of both the “before” and “after” flatfish conditions. The picture above is of a larval flatfish we found in the plankton. If you have to look closely at the photo, you can see that it still has only one eye on each side of its head! The fish will eventually undergo metamorphosis, during which its entire skull will twist, and one eye will migrate over to the other side of its head! The whole process takes between 5 days and a few hours, depending on the species of flatfish. This leaves flatfish with a blind side (the one with no eye), which it can keep buried in the sand. Check out the video below to see this metamorphosis in action!