Meet the Pteropods

Dec 13, 2011 by  | Bio |  Leave a Comment

Image courtesy of Arctic Exploration 2002, Russ Hopcroft, University of Alaska, Fairbanks, NOAA/OER

Sharks need pteropods, and so do you! At the risk of looking at the world through shark-shaped glasses, let me explain.

Pteropods are little mollusks (related to snails, slugs and squid) that drift around in ocean currents, feeding on nutrient-rich plankton. Their rich diet makes them delicious to many fish. Seals eat many fish, and sharks eat seals and fish, so there it is: not even 6 degrees of shark separation. Sharks need pteropods, and so do you.

Pteropods are gorgeous. People get poetic when they talk about them. Pteropods with shells are sometimes called “sea butterflies” and the shell-less ones are deemed “sea angels.” But good luck seeing them. The ones around here are tiny. According to Woods Hole Oceanographic Institution (WHOI) pteropod researcher Amy Maas, the biggest they get is about 1/10 of an inch. Visible to the naked eye, but you probably couldn’t see their little faces. Small though they may be, unimportant they are not. Just ask the sharks.

As tiny sea creatures borne by currents, pteropods are individually delicate. Unfortunately, those with shells are under threat from ocean acidification (OA). I’ll be writing more about OA in the coming months, but here are the basics.

The carbon dioxide we are cranking into the atmosphere in unprecedented quantities does not just hang around heating up the planet, it also changes the chemistry of the oceans. The gases in the ocean must be at equilibrium with the gases in the air, so when CO2 concentrations increase in  the air, some of it dissolves into the ocean to achieve that balance. This forms carbonic acid, which decreases the pH of the water, making it more acidic. Ocean Acidification.

This is not good news for these little mollusks, since the minerals they need to grow shells are less available in the acidic water. WHOI scientist Gareth Lawson and other ocean researchers are trying to figure out exactly what will happen to our “charismatic microfauna” as the ocean pH drops. I’ll keep you posted. For now, check out this site about pteropods and OA (don’t miss the song at the bottom, it’s super catchy)

Carbon pollution and ocean acidification are not just New England issues. Yet, while OA is a global problem, there are things we can do right here, right now, to help.

CLF is working hard to prevent further harm and to give our abundant ocean life a chance to thrive. We are promoting clean energy and reductions in greenhouse gas emissions to help stop OA and other negative effects of climate change. We are supporting a climate friendly modernized public transportation network. And we support our National Ocean Policy which calls for immediate steps to protect critical marine habitats, ensure a sustainable future for our fishing industry and coastal communities, reduce coastal pollution and promote the responsible development of offshore renewable energy.

By the way, according to the Shark Week Countdown Clock, only 231 more days to go!

Discovery Channel responds: Show about polar environment will talk climate change

Nov 18, 2011 by  | Bio |  Leave a Comment

Quick update on subject of a blog post the other day.

Discovery Channel, in an article posted on Treehugger (which discloses it is owned by Discovery Communications, the parent of Discovery Channel) claims that the climate change content in the US version of Frozen Planet will be the same as in the BBC version – that they will simply be re-editing the show to fit into six episodes and with an American accented narrator.  Apparently our ears are not sophisticated enough to appreciate the dulcet tones of Sir David Attenborough.

And as to the climate issue, as Treehugger concludes, the proof will come when the show airs . . .

Discovery Channel wimps out – Not airing pivotal climate episode of acclaimed “Frozen Planet” series

Nov 16, 2011 by  | Bio |  Leave a Comment

The good news: cable TV outlet the Discovery Channel co-produced, with the BBC,  a nature series about the polar regions entitled Frozen Planet working with award winning director David Attenborough.   Discovery has proudly announced their co-ownership of the series, which is airing in Britain now (and apparently is quite hit) and will be shown in the US on Discovery in 2012.

The bad news: Discovery (who I admit has gotten some free publicity from us for their Shark Week) has decided to not show the final episode in the series that presents the threats, particularly in the form of global warming, that man poses to the polar environment. In the words of an incredulous headline of a newspaper article in Britain’s Daily Mail: “Climate change episode of Frozen Planet won’t be shown in the U.S. as viewers don’t believe in global warming.”

Protecting our climate will require systematic action across our society and economy.  As President Obama just noted in remarks in Australia it will be, “a tough slog, particularly at a time  when a lot of economies are struggling.”  But it is a transition that (as he went on to say) can build up jobs and the economy and “that, over the long term, can be beneficial.”

But if we don’t talk about the problem and don’t show the impacts of global warming, let alone the solutions what are the chances of our nation and the world taking on and solving this most fundamental of problems?


In Honor of Shark Week: Why I Love Sharks

Aug 1, 2011 by  | Bio |  2 Comment »

(Photo credit: NOAA Photo Library)

It’s more of an obsession, really. I spend a lot of time in the water: surfing, boogie boarding with my kids, or just cooling off. I think about sharks every time I get in the ocean. If I haven’t had a good long think about them before I get in, then I ponder their existence as soon as I’ve made it out past the break and I’m dangling my feet off the sides of my seal shaped surfboard. If you meet a surfer who says they don’t think about sharks, they are lying.

So, why the love? Well, I love the ocean. I love a balanced ecosystem. I love eating fish and shellfish. Sharks are one of our more exciting apex predators. An apex predator is the one at the top of the food chain that keeps the populations in check all the way down the line. Recent studies on shark populations have found that a drop in shark numbers leads to plummeting shellfish populations. Sharks eat other predatory fish, as well as rays and other animals that feed on shellfish. Once the sharks are gone, the clams, scallops and oyster populations are preyed on heavily by animals that would normally not be so abundant.  Unfortunately, sharks are declining precipitously around the world. Sharks are taken intentionally for “finning” (the removal of fins for shark fin soup), and unintentionally as bycatch during the fishing of other species. Marine scientists aren’t exactly sure how things would play out if sharks were gone, but none of the scenarios are good.

In “A Sand County Almanac,” Aldo Leopold wrote about one of the apex predators of the west. In his days with the Forest Service there was a mass kill policy for wolves. As a result, deer populations exploded. This led to major overgrazing of mountain vegetation. Erosion and river-choking sedimentation are a couple of the problems associated with overgrazing. Leopold wrote: “I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer.” This was a formative part of his land ethic. Simply put “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.”

The release last year of our National Ocean Policy (NOP) was a big step in promoting a saltwater version of this ethic. CLF’s Priscilla Brooks had this to say about the newly created NOP: “For the first time in this country’s history, we will have a national policy that aligns the great promise of our oceans with the great responsibility for managing them in a coordinated, thoughtful and sustainable fashion. New England has led the charge to balance the ever-increasing interest in our state waters … with the need to protect wildlife and critical habitat areas so that our region’s oceans will continue to be productive for generations to come. From Massachusetts to Rhode Island to Maine, we are developing ocean management plans that will serve as guides for better protection and management in federal waters across the nation.”

Ecosystem-based management is at the heart of the NOP. Healthy shark populations are just one facet of a balanced ecosystem. Seal populations have been recovering after near decimation from hunting (and a thriving shark population will keep the seals in check). Some commercial fish populations are now recovering from decades of overfishing. Shellfish, seals, sharks, commercial fish – all are linked. We can’t “manage” one without the effects cascading through the others. Ecosystem-based ocean management plans will consider these connections.

So, even as I picture just what it would look like if a great white shark came rushing from the depths for a neoprene-wrapped snack (me), I still love sharks.  I try to be sensible. I avoid the water at dawn and dusk (unless the waves are really good). I stay in shallow water. I get out of the areas where seabirds are working – evidence of major food chain activity. And I’ll take a shark sighting as seriously as anyone. But, since sharks are essential for thriving, productive oceans, they are good to have around. Even if I don’t want them around me.