National Geographic contributing photographer Paul Nicklen gets up close and personal with a Leopard Seal in Antarctica who thought he was a “useless predator.”

The sponge pieces or explants are now healed and ready to be used in the climate change study. To determine the effects of warmer, more acidic waters (= lower pH) on coral reef sponges, we are comparing today’s environmental conditions to what is expected by 2100. But to determine what factor (i.e. temperature or pH) is most important for sponges, we are separating them into 4 treatments: 1) current temperature and pH, 2) current temperature and low pH; 3) high temperature and current pH; and 4) high temperature and low pH. Treatment 1 is called the control, as it is just the normal conditions of today.  Treatments 2 and 3 will help us determine the individual effects of warmer water and lower pH.  Treatment 4 mimics the predicted future environmental conditions of our oceans.

The experimental setup showing two rows of tanks, large grey CO2 bottles topped with regulators that feed the gas, via the green pH controllers, into the water.

To maintain constant conditions for each treatment, we are conducting the study in large tanks at the wet-lab at the Discovery Bay Marine Laboratory. Water temperature is controlled by using heaters, the same kind you can get in any aquarium store.  To manipulate pH, we are going hi-Tec, and bubbling CO₂ into the water. Stored at high pressure in large bottles, CO₂ is slowly released at low pressure through regulators, which feed the gas into tubing that snakes into the water. The regulators are turned on (to release gas) or off (to shut gas supply) by pH controllers that use a probe to determine the exact pH of the seawater in the tanks. The pH controller will only turn the regulator on when the pH of the water goes above a certain level (turning on the CO₂ will make the water more acidic, lowering the pH). Every tank is “flow through”, meaning seawater constantly enters and drains through a pipe.  Each tank also has three tubes bubbling air.  The flow through system and additional air bubblers ensures that all waste products from the sponges are removed, and that they have sufficient food and oxygen.

One tank containing a heater (long, blue object), tubing to supply air and CO2, and 6 species of coral reef sponges, each with 5 explants.

As you can imagine, setting up the experiment  involved several days of cutting tubing, feeding extension cords across the room, adjusting the water flows, aeration and pH just right, and countless swatting of mosquitoes that plague the wet-lab. It also involved some on the spot innovation (and frustration) as some of the expensive equipment we had just purchased malfunctioned. Thankfully, we circumvented the problems through some creative reconfigurations. I’m now happy to report that we have several hundred explants of 6 common coral sponge pieces growing in tanks. This experiment will run for 1 month, and at the end we will compare sponge growth, survival and chemistry (what chemicals the sponges are producing) among the 4 treatments to see what effects, if any, temperature and pH change will have on tropical sponges.

5 explants of a coral reef sponge.

Monday afternoon I arrived in Jamaica to study the effects of climate change (warmer, more acidic waters) on coral reef sponges. Similar to the study examining climate change effects on a boring sponge (see previous blog), this study will be done in tanks on land. But this time we’ll be using heaters to warm the water and CO₂ regulators and controllers to control the water’s pH. I had to buy all the necessary equipment in the USA and bring it with me on the plane. Arriving in Jamaica, the custom officers were very interested in my two bags full of aquarium supplies and I spent some time explaining why I needed 15 aquarium heaters and other assortments, but thankfully they let me through. After my colleague Marah Hardt arrived a few hours later, we got a taxi to the Discovery Bay Marine Laboratory. The following day was spent setting up some of the experimental equipment (which I will describe in a later blog), and today we collected sponges.

ready to dive

 

The coral reefs around Jamaica and throughout much of the Caribbean are dominated by sponges. Displaying all the colors of the rainbow, and ranging up to 5 ft long, sponges are both conspicuous and impressive. This study will focus on sponge species that are common throughout the Caribbean region like the yellow tube sponge, Aplysina fistularis, and the octopus sponge, Ectoploysia ferox.

Aplysina fistularis and fish (in tube)

Sponges have remarkable regenerative abilities, allowing us to remove a small piece, leaving the rest behind. This will heal within a few days and grow back the cut portion in a few weeks or months.

cutting sponges underwater

cut sponge

This cut portion is taken back to the lab and cut into smaller pieces or explants. After the explants are fully healed (in a few days) we will use them to examine the effects of climate change.

cutting the sponges into smaller pieces (explants)

This study will run for about 1 month and is generously funded by the Disney Worldwide Conservation Fund.

As climate change results in warmer, more acidic waters, all marine life is affected. Recent studies have determined that the effect of climate change on marine animals that have a calcium carbonate skeleton like corals, shellfish and pteropods will be severe, with the possible loss, for example, of many coral reefs by 2100. The effect of climate change for many marine animals, like sponges, is simply not known.

The Azure Vase Sponge, Callyspongia plicifera

Sponges filter and clean the water, provide shelter for commercially important species like juvenile lobsters, and are eaten by many fish and turtles. There are over 8,000 species of sponges living in our oceans, from polar to tropical waters, form the abyss to the intertidal zone. All sponges are sessile, mostly living on hard bottom substrate like rock. Some species are boring sponges, able to bore into the shells of clams, scallops and other shellfish. Over time this weakens the shell, eventually killing the shellfish. The rate of sponge boring may increase as shells get weaker due to climate change, negatively impacting shellfish populations worldwide and shellfish farmers who commercially grow mussels, clams and scallops.

A study by Blue Ocean Institute and Stony Brook University, New York, is examining whether the growth and boring rates of a common boring sponge, Cliona celata, will increase as our oceans become warmer and more acidic (lower pH). We are testing four treatments that differ in pH and temperature based on today’s values and the predicted values for 2100: 1) current temperature and pH, 2) current temperature and low pH; 3) high temperature and current pH; and 4) high temperature and low pH.

Thomas Behling, from Stony Brook University, monitoring the experiment. The two large blue buckets are reservoirs that hold seawater at pH of 7.8 and 8.1., which gravity-feeds into the experimental tanks below holding the sponges.

Normally in the wild, sponge larvae would attach to scallop shells but in this study we are using small “adult” sponges, which are secured onto scallop shells using rubber bands. Once the sponge has attached to the shell, the rubber band is removed. Preliminary results are very interesting. After 1 month, attachment is nearly 100% for sponges at current (today’s)  pH regardless of water temperature. However, only two-thirds of sponges in the more acidic water treatments (lower/future pH) have attached. This suggests that at least for sponge attachment, pH has a greater impact than water temperature, probably through stressing the sponges. This study will run for a few more months to fully determine the impact of climate change on a temperate (cool water) sponge species.

The boring sponge, Cliona celata, attached to a scallop shell

Tropical sponges, such as those that live on coral reefs, may also be affected by warmer, more acidic water. To test this I’m off to Jamaica next week, courtesy of the Disney Worldwide Conservation Fund, to determine the effects of climate change on coral reef sponges. I’ll be posting regular blogs detailing the experiment and results, so stay tuned.

October is Seafood Month and it is the perfect time to launch a new addition to the Blue Ocean website. For me, seafood is the most engaging and compelling ingredient. The rich bounty of textures and tastes makes cooking it a lot of fun. Many of the species that we most commonly enjoy as seafood are not faring so well in their lives as fish. We have put enormous pressure on populations to provide for us and those populations are suffering from it. However, many of the species not faring so well are easily replaced in tonight’s dinner by some delicious and ocean-friendly options. What is great about seafood is the possibility to substitute is nearly infinite and in the process you might find a new more sustainable favorite.

In the new section of the website, we pose some ideas for exploring new species and using something maybe a little unfamiliar in a familiar way. Ocean-friendly seafood isn’t difficult and it is not about giving up seafood. It is about paying attention to what we eat. It is about supporting those who work the waters to provide for us. And ultimately, it is about us and the communion we all share, dinner.

~ barton seaver

Check out Barton’s new section on the Blue Ocean website, I’m Just Here For Dinner.  There’s recipes, including videos, and a listing of ocean-friendly substitutes for you to try for dinner tonight.

Scientists recently captured images of Black-browed Albatrosses (Thalassarche melanophrys) following a Killer Whale.

A camera showed albatrosses following a whale, perhaps for food. (courtesy of the British Antarctic Survey)

Scientists from Hokkaido University in Japan and the British Antarctic Survey attached cameras and depth and temperature sensors (all weighing less than 3 ounces!) to four birds in the southern Atlantic.

They reviewed the photos and data taken and noticed an image that captured fellow Albatrosses following a Killer Whale.  Using data from the depth sensors, the scientists were able to tell the Albatross fitted with the camera was was actively diving at the time of the Killer Whale pic (as opposed to infrequently at other times).

So what does it all mean?  It’s thought that the Albatrosses were feeding on scraps left behind by the whale, which “may partially explain how albatrosses find their prey more efficiently in the apparently ‘featureless’ ocean, with a minimal requirement for energetically costly diving or landing activities”.  Read the full article anstract here.

Stephen Colbert sure knows how to get a guffaw over serious issues.  Tuesday night he had “Her Deepness,” Dr. Sylvia Earle, as a guest on his Comedy Central show The Colbert Report - you may recall we honored Sylvia at our 2007 Gala.  Sylvia talks to Colbert about her new book, The World Is Blue, and why the ocean is so important to all life on Earth.

Click here to view the interview!

Haddock are a demersal (=bottom-living) fish found throughout the coastal regions of the North Atlantic, from northeast U.S. to Norway. Related to Atlantic cod, Haddock are commercially fished throughout their range, with most caught using bottom trawling. After decades of overfishing, good management and strong recruitment in recent years has promoted high abundances in some regions. Decades of fishing pressure, however, has changed their life history characteristics.

Haddock (image from aquanic.org)

Before 1970, Haddock would typically take 4 years to reach 50 cm in length, but during the 1980’s and 90’s most Haddock reached this size within 3 years. Today, it’s again about 4 years. These changes likely result from density-dependent growth rates. When Haddock are uncommon, due to overfishing, there is little competition for food so the few remaining Haddock grow fast. At high abundances, competition for food is intense and growth is comparatively slow.

Age at sexual maturity has also changed, with most female Haddock reproducing now at 3 years instead of 4 years. For most fish species, however, fecundity or the number of eggs produced is related to body size/age, with older and larger females producing more eggs. Although maturing quicker has increased the spawning stock biomass (i.e. more sexually mature Haddock), reproductive success and the number of juvenile fish entering the population may actually be lower in years to come.

BOI has recently ranked Haddock and found that it has a “yellow” score, so a better alternative than red-listed Atlantic Cod but not as sustainable as green-listed Walleye Pollock and Pacific Cod.

http://www.blueocean.org/seafood/seafood-view?spc_id=25

Mediterranean countries block tuna fishing ban

There’s been a lot of back and forth with European nations grappling over whether they should list Atlantic bluefin tuna under the Convention on International Trade in Endangered Species (CITES), a move that would allow this dwindling species to recover.  Well, the decisions are in and unfortunately the EU has decided to back out of what would have been a substantial step in the right direction for Atlantic bluefin tuna recovery.

The following article appeared in the EU Observer on 9/22/09:

LEIGH PHILLIPS

22.09.2009 @ 09:13 CET

EUOBSERVER / BRUSSELS – The European Union has abandoned its plans to push for a temporary ban on fishing for bluefin tuna, loved by sushi fans but severely overfished, after strong opposition from Mediterranean countries.

National experts from EU member states met on Monday (21 September) to consider a proposal from the European Commission to back a pause in the fishing of the species, but France, Spain, Italy, Malta, Greece, and Cyprus baulked at the suggestion, even though France had earlier said it would back the plan.

As a result of the obstruction, led by Spain and Malta, the officials were unable to reach the necessary majority to adopt the commission’s recommendation.

The EU executive on 9 September had proposed that the bloc co-sponsor alongside non-EU country Monaco a temporary suspension on international trade in Atlantic bluefin tuna under the Convention on International Trade in Endangered Species (CITES).

The ban through a CITES listing would give the fish a chance to recover, the commission argued.

The proposal to list the tuna as an endangered species was originally tabled by Monaco in July at the International Commission for the Conservation of Atlantic Tunas (ICCAT), the inter-governmental body responsible for the conservation of tuna.

At the time, French President Nicolas Sarkozy backed Monaco’s suggestion alongside a number of other EU states, including the UK, the Netherlands, Germany, Poland and Austria.

Monday’s move postpones a decision on whether to place bluefin tuna on an endangered species list. EU environment ministers are now expected to reach a final position by the end of the year.

Conservationists were frustrated by the reversal.

“The blinkered attitude of Mediterranean governments would drive bluefin tuna to extinction and leave fishermen with nothing to fish in just a few years,” said Saskia Richartz, a campaigner with Greenpeace in Brussels.

“But countries like Malta and Spain are increasingly isolated and there is a growing will among EU environment ministers to save this beautiful animal,” she added.

EU environment commissioner Stavros Dimas issued a statement in which he said he “regrets the decision”.

“The commission has expressed its grave concerns about the state of stocks of the fish, which are rapidly declining after decades of overfishing,” the statement continued.

Click here to view the original article.

Yesterday the Associated Press ran a story about the Western Pacific nation of Palau, who announced today at the United Nations its ban of shark fishing.  

Blue Ocean President, Carl Safina reflects below on how shark populations have plummeted over the years and that Palau is making groundbreaking efforts to reverse this tragic trend:

I and everyone I’ve ever spoken to in any ocean can tell you that sharks are much scarcer than in the 1980s, and that catch rates are much lower. In fact, some species have virtually vanished from large areas.
 
Many older fishermen can tell you that sharks were abundant swimming near the surface in the 1960s, and that they’d usually see 50 or more over the course of a day. In those days, “finning” meant swimming along the surface with their fins sticking out of the water.
 
Most impressive to talk with, in my experience, are people who used to be aerial swordfish spotters here in the Northeast US. They

photo courtesy of Dan Klotz

 can tell you there were so many sharks through the 1970s that the hardest thing about finding a swordfish (which were common then, too) was to spot one amidst all the sharks.
 
While diving in Palau earlier this year, I had the impression that sharks remain common but not as abundant as in the mid-1990s.

Some sharks range large areas, so even shark fishing hundreds of miles away could greatly affect shark numbers in another area. However, this shark sanctuary is very welcome news. It’s big enough that if it can be patrolled effectively—and that’s a big ‘if’—it could make a real difference for the shark population of Palau.
 
Palau has continually done an outstanding job of turning living fish into sustainable cash. Early on, Palau banned the export of reef fishes, and as a result it has some of the best reef fish populations remaining in the world.
 
As reefs deteriorate and get stripped of fish elsewhere, Palau becomes increasingly valuable not just biologically but as a tourist destination, an ongoing cash cow for Palau itself. It is perhaps the best place in the world to see large humphead or Napoleon wrasse, now rare elsewhere. And because certain fish graze algae from coral reefs, overfished reefs elsewhere are overrun with coral-smothering algae.

photo courtesy of Dan Klotz

By contrast, Palau’s reefs are not only healthy but actually have recovered from widespread coral bleaching in the late 1990s. The bleaching was caused by abnormally hot water related to global warming. In most places, a reef with so many dead corals would have been quickly overrun by algae that would have prevented corals from regaining their foothold. That means the end of coral reefs in some areas. But in Palau, the still-abundant fishes suppressed the algae, allowing reefs to recover.
 
Palau’s visionary protection of reefs and the banning of shark fishing are policies of very high value not just to Palau itself, but increasingly, for the rest of the world as well.