Text by American Chemical Society, Photo by NOAA



In the first study to look at what happens over the years to the billions of pounds of plastic waste floating in the world's oceans, scientists are reporting that plastics -- reputed to be virtually indestructible -- decompose with surprising speed and release potentially toxic substances into the water.

Reporting at the 238th National Meeting of the American Chemical Society (ACS), the researchers termed the discovery "surprising." Scientists always believed that plastics in the oceans were unsightly, but a hazard mainly to marine animals that eat or become ensnared in plastic objects.

"Plastics in daily use are generally assumed to be quite stable," said study lead researcher Katsuhiko Saido, Ph.D. "We found that plastic in the ocean actually decomposes as it is exposed to the rain and sun and other environmental conditions, giving rise to yet another source of global contamination that will continue into the future."

He said that polystyrene begins to decompose within one year, releasing components that are detectable in the parts-per-million range. Those chemicals also decompose in the open water and inside marine life. However, the volume of plastics in the ocean is increasing, so that decomposition products remain a potential problem.

Each year as much as 150,000 tons of plastic debris, most notably Styrofoam, wash up on the shores of Japan alone, Saido said. Vast expanses of waste, consisting mainly of plastic, float elsewhere in the oceans. The so-called Great Pacific Garbage Patch between California and Hawaii was twice the size of Texas and mainly plastic waste.

Saido, a chemist with the College of Pharmacy, Nihon University, Chiba, Japan, said his team found that when plastic decomposes it releases potentially toxic bisphenol A (BPA) and PS oligomer into the water, causing additional pollution. Plastics usually do not break down in an animal's body after being eaten. However, the substances released from decomposing plastic are absorbed and could have adverse effects. BPA and PS oligomer are sources of concern because they can disrupt the functioning of hormones in animals and can seriously affect reproductive systems.

Some studies suggest that low-level exposure to BPA released from certain plastic containers and the linings of cans may have adverse health effects.

Saido described a new method to simulate the breakdown of plastic products at low temperatures, such as those found in the oceans. The process involves modeling plastic decomposition at room temperature, removing heat from the plastic and then using a liquid to extract the BPA and PS oligomer. Typically, he said, Styrofoam is crushed into pieces in the ocean and finding these is no problem. But when the study team was able to degrade the plastic, it discovered that three new compounds not found in nature formed. They are styrene monomer (SM), styrene dimer (SD) and styrene trimer (ST). SM is a known carcinogen and SD and ST are suspected in causing cancer. BPA ands PS oligomer are not found naturally and, therefore, must have been created through the decomposition of the plastic, he said. Trimer yields SM and SD when it decomposes from heat, so trimer also threatens living creatures.

Text and Photo by Liz Clark



While waiting for word from the French embassy in California about a visa extension that will allow me ample time to go back and fix Swell in Tahiti, the Patagonia crew invited me to fly down and join them on a surf trip...

So, I bounced from a wedding in Hawaii (congrats Jon and Nicole!), to working on a book in Portland (where I also became an avid bike commuter, jazzerciser, and peed-in wetsuit model), to the exciting premieres of the "Dear and Yonder" surf film in Encinitas and Ventura, to an outbound adventure for south swell on the Central Coast with Blakeney and Bennett, to a night of music and friends and photos from my voyage at the Brewhouse in Santa Barbara (thank you Tucker!), to a week of family boating fun in Catalina for my dad's birthday (which, also included two clogged toilets, two disagreeable outboards, and a stubborn packing gland). Then, straight into a frenzy of packing, a rode trip to LAX with Anna, and then, 26 hours later, a little island off Bali where I found my friend Katie, a few lovely rights, and took a crash course in Balinese and motorbike riding. We hugged goodbye yesterday after she piggy-backed me to the ferry boat to keep the fresh reef scratches on my foot dry, and I was off to get a quick taste of Kuta before jumping a domestic flight to Jakarta where I've found an internet connection in the Jakarta Airport Hotel that's working long enough for me to type this. The boys just arrived...not sure what I'm doing here with a crew like Gerry Lopez, Wayne Lynch, and the Malloys, but they probably just wanted someone who can tie knots and wax boards? We're off on a boat trip tomorrow where my toughest decisions will be which board to ride and bikini to wear! No dishes, anchor pulling, or night watches, huh? I won't know what to do with myself.

I miss Swell dearly, but she knows I'll be back soon to fix her, I'm just doing a bit of reconnaissance farther west so as best to choose our route through this region a few seasons from now.

---

Liz Clark sails solo around the world on her 40-foot sailboat, Swell, in search of people, places and waves. She sends us travel updates, stories and photos several times a week.

More travel logs

More photos of the trip

Text and Photo by NOAA



Sandbar, dusky and tiger sharks are among dozens of shark species living in the coastal waters off the U.S. East Coast. Little is known about many of the species, but a survey begun nearly 25 years ago is helping scientists and fishery resource managers to monitor shark populations and their role in marine ecosystems.

NOAA scientists from the Northeast Fisheries Science Center (NEFSC) lab in Narragansett, R.I., recently conducted their ninth coastal shark survey from Florida to Delaware. The survey, conducted every two to three years, is the longest survey independent of the fishing industry of large coastal sharks in the U.S. Atlantic Ocean.

Using commercial Florida-style longline fishing methods to standardize results from survey to survey, researchers caught 1,675 sharks from 19 different species and tagged 1,352 individuals during the 2009 survey in April and May. Most of the animals caught and tagged were sandbar sharks, a common species in the western Atlantic. Longline fishing is a type of fishing that uses a long or main line with baited hooks spaced out at certain intervals along the line.

"During the survey, we often catch 19 or more species, many of which are highly migratory, and we still have a lot to learn about them," said Nancy Kohler, who heads the Apex Predators Program at the Narragansett Lab and has been on every survey. "We do not know how large certain species are when they mature, for example. It is important that we obtain basic biological information from the fish we catch so that we can learn as much as possible about their life histories, or the changes that the animals undergo from birth to death."

Researchers record the length, sex and location of each animal caught before the fish is tagged and released. The sharks can range from 1 foot to 15 feet; they are not weighed. Any dead fish are carefully dissected at sea, with researchers looking for parasites, collecting DNA and blood samples, and obtaining samples for studies of age and growth, reproductive biology and food habits.

The first systematic survey of Atlantic sharks was conducted by the Apex Predators Program in 1986 between Florida and southern New England waters from 5 to 200 meters deep (about 16 to 660 feet). In addition to basic biological information, researchers gather data on shark abundance and distribution and migration patterns.

Kohler said the survey is conducted in the spring because coastal shark species distributions are concentrated during this time of year since the waters north of Delaware are too cold, thus making it easier to survey the whole population. Nearly all of the surveys have been conducted from the NOAA ship Delaware II, based at the NEFSC's Woods Hole Laboratory.

"We caught more fish and tagged more fish on this survey than any other," said Lisa Natanson, who heads the coastal survey effort and has been on all but one of the surveys. "The previous high total was in 1998, when we caught 917 sharks and tagged 859. Some years we catch very few, so it really varies." In addition to numerous sandbar sharks, the researchers also caught one great white, many tiger and dusky sharks, and some Atlantic sharpnose. The current data are part of just one of several long-term data sets that are used to determine the health of shark populations.

The survey takes six weeks to complete and is divided into three legs, each approximately two weeks long. Eight scientists are on board for each leg, and fishing is conducted around the clock. Environmental information, such as water temperature and ocean chemistry, is obtained at each station.

Survey data are provided to the fishery managers who monitor populations in the Atlantic and Gulf of Mexico. NOAA Fisheries Service manages the commercial and recreational shark fisheries in U.S. waters, including the Caribbean Sea and the Gulf of Mexico. The United States began regulating shark fisheries in 1993 and currently manages 39 species. A fishery management plan that includes sharks, swordfish, and tunas went into effect in 1999, regulating sharks under a catch limit and quota system.

In addition to the coastal shark survey, Kohler, Natanson and colleagues in the Apex Predators Program work with thousands of volunteers throughout the Atlantic Ocean, Gulf of Mexico and the Mediterranean Sea through the Cooperative Shark Tagging Program10./. The lab also manages and coordinates the Cooperative Atlantic States Pupping and Nursery Survey, collaborating with researchers in coastal states from Rhode Island to Florida to conduct a comprehensive and standardized investigation of shark nursery areas.

Scientists in the program conduct life history studies of commercially and recreationally important shark species, participate in and conduct a variety of research cruises, and often go aboard commercial vessels to obtain biological samples from the catch as well as to tag sharks. Biological samples are also collected from recreational fishing tournaments in the Northeast U.S.

Text and Graphic by Queen's University Belfast



A giant new machine called 'Oyster' designed to harness the power of ocean waves and turn it into 'green' electricity is being installed on the seabed off the Atlantic shores of the Orkney Islands. In autumn 2009 it will undergo demonstration trials to prove whether its innovative technology could lead to a commercial source of renewable energy for use in seashores around the world.

In contrast to many other wave power devices, Oyster uses hydraulic technology to transfer wave power to shore, where it is then converted into electricity. 'A key design feature is a 18m wide oscillator based on fundamental research at Queen's University Belfast led by Professor Trevor Whittaker using their wave tanks', explains Dr Ronan Doherty, Chief Technical Officer of Aquamarine Power the Edinburgh based company which has developed the first 'Oyster'. The oscillator is fitted with pistons and, when activated by wave action, pumps high-pressure water through a sub sea pipeline to the shore. Onshore, conventional hydroelectric generators convert this high-pressure water into electrical energy.

'The whole field of generating electricity from wave power is ground breaking' says Dr Doherty, 'But Oyster' technology is highly innovative because it relies on simplicity. Its offshore component -a highly reliable flap with minimal submerged moving parts - is the key to its success when operating in seas vulnerable to bad weather where maintenance can be very difficult. There is no underwater generator, power electronics or gearbox underwater to go wrong. All the complex power generation equipment remains easily accessible onshore'.

Oyster is designed to be deployed at near-shore water depths of 12 to 16 metres, benefiting from the more consistent seas and narrower directional spread of the waves in this location. The reduced wave height and load enhance survivability and allow a high percentage of annual average power and consistent power delivery. Any excess energy is spilled over the top of the flap, its rotational capacity allowing it to literally duck under the waves.

The environmental risks associated with the device are minimised by using only water as its hydraulic fluid, rather than oil, and there are no toxic substances involved. It is also silent in operation. Based on figures from the Carbon Trust, each Oyster's annual carbon saving could be as much as 500 tonnes.

Although at an early stage of development, the Oyster concept could have significant potential for use in many locations around the world. Dr Doherty explains: 'Our computer modelling of coastlines suitable for this technology shows that Spain, Portugal, Ireland and the UK are ideal candidates in Europe. But globally there is huge scope in areas like the North West coast of the USA and coastlines off South Africa, Australia and Chile. We estimate that the potential size of the market could be in excess of 50 billion'.

Text by San Francisco State University, Photo by NOAA



Stories of ships mysteriously sent to watery graves by sudden, giant waves have long puzzled scientists and sailors. New research by San Francisco State professor Tim Janssen suggests that changes in water depth and currents, which are common in coastal areas, may significantly increase the likelihood of these extreme waves.

Published in the Journal of Physical Oceanography, Janssen's wave model simulations show that focusing of waves by shoals and currents could increase the likelihood of a freak wave by as much as 10 times. Although scientists cannot predict the occurrence of individual extreme waves, Janssen's findings help pinpoint conditions and locations favorable for giant waves.

Extreme waves, also known as "freak" or "rogue" waves, measure roughly three times the size of the average wave height of a given sea state. Recorded monster waves have exceeded 60-feet -- the approximate size of a six-story building. Janssen's research suggests that in areas where wave energy is focused, the probability of freak-waves is much greater than previously believed.

Wave focal zones are particularly common in coastal areas where water depth variations and strong currents can result in dramatic focusing of wave energy. Such effects are particularly well known around river mouths and coastal inlets, restricting accessibility for shipping due to large, breaking waves near the inlet, or resulting in erosion issues at nearby beaches. Extreme examples of wave focusing over coastal topography include world-class surf spots, such as Mavericks and Cortez Banks in California. The identification of freak wave hot spots is also important for shipping and navigation in coastal areas, and the design of offshore structures.

"In a normal wave field, on average, roughly three waves in every 10,000 are extreme waves," Janssen said. "In a focal zone, this number could increase to about three in every 1,000 waves. In a focal zone, the average wave height is already increased due to the focusing of energy so that an extreme wave in such a high energy area can potentially be very energetic and dangerous."

Janssen's wave simulations estimated the evolution of waves in open oceans, waves interacting with an opposing current, and waves traveling over a topographical feature such as a reef. The simulations show that freely developing waves maintain normal statistical properties with a small likelihood of extremes. But when the waves are focused by variations in water depth or currents, the rapid increase in energy drives wave interactions that enhance the likelihood of extreme waves.

"We found that if the focusing is sufficiently strong and abrupt, wave interactions create conditions favorable to extreme waves," Janssen said. "When we gradually increase the focal strength, initially wave interactions are weak and statistics remain normal. However, when increasing the focal strength beyond a certain threshold, suddenly wave interactions are enhanced and freak waves are much more likely than normal. It appears that wherever waves undergo a rapid transformation, freak waves can be much more likely than we would otherwise expect."

Text by Polytechnic University of Catalonia, Photo by CIRCE



Two researchers from the Polytechnic University of Catalonia (UPC) and the University of Aberdeen in the United Kingdom have shown for the first time that the law of brevity in human language, according to which the most frequently-used words tend to be the shortest, also extends to other animal species. The scientists have shown that dolphins are more likely to make simpler movements at the water surface.

"Patterns of dolphin behavior at the surface obey the same law of brevity as human language, with both seeking out the simplest and most efficient codes", Ram n Ferrer i Cancho, co-author of the study published in the journal Complexity and a researcher in the Department of Languages and IT Systems at the UPC, tells SINC. The law of brevity, proposed by the American philologist George K. Zipf, along with others, shows that the most frequently-used words are the shortest ones.

Ferrer i Cancho, together with the scientist David Lusseau from the University of Aberdeen in Scotland (although they actually carried out this study while working at the Universities of Barcelona and Dalhousie in Canada, respectively) have shown that when dolphins move on the surface of the water they tend to perform the most simple movements, in the same way that humans tend to use words made up of less letters when they are speaking or writing, in so-called "linguistic economy".

The research study includes the case of Oscar Wilde's novel The Picture of Dorian Gray. The most-used word is the three-letter article "the", while other larger ones, such as "responsibilities" are hardly found at all. Among bottlenose dolphins in New Zealand, the researchers looked at their behavior patterns at the surface of the water. Each pattern is made up of up to four basic units.

So, the "tail slap" pattern is made up of the units "slap", "tail" and "two", while the "spy hop" pattern is made up of the units "stop", "expose" and "head", and the "side flop" pattern" comprises "leap" and "side", and the "tail-stock dive" only involves the "dorsal arch" unit.

In total, the scientists counted more than 30 patterns of behavior and their related units, and have shown that dolphins carry out more behavior patterns made up of just one unit, while those involving four units are used less frequently.

"The results show that the simple and efficient behavior strategies of dolphins are similar to those used by humans with words, and are the same as those used, for example, when we reduce the size of a photographic or video image in order to save space", says Ferrer.

The researcher says that studies such as this one show that human language is based on the same principles as those governing biological systems, "which leads us to the conclusion that the traditional barriers between disciplines should be removed".

Text by NRDC, Photo by US Park Service



The water at American beaches was seriously polluted and jeopardized the health of swimmers last year with the number of closing and advisory days at ocean, bay and Great Lakes beaches reaching more than 20,000 for the fourth consecutive year, according to the 19th annual beachwater quality report released today by the Natural Resources Defense Council (NRDC).

"Pollution from dirty stormwater runoff and sewage overflows continues to make its way to our beaches. This not only makes swimmers sick - it hurts coastal economies," said Nancy Stoner, NRDC Water Program Co-Director. "Americans should not suffer the consequences of contaminated beachwater. From contracting the flu or pink eye, to jeopardizing millions of jobs and billions of dollars that rely on clean coasts, there are serious costs to inaction."

Using data from the U.S. Environmental Protection Agency, NRDC's report - Testing the Waters: A Guide to Water Quality at Vacation Beaches - confirms that our nation's beachwaters continue to suffer from serious contamination - including human and animal waste - that can make people sick.

NRDC's report also provides a 5-star rating guide for 200 of the nation's most popular beaches, based on indicators of beachwater quality, monitoring frequency, and public notification of contamination.Five-star beaches included Gulf Shores Public Beach (AL), Laguna Beach-Main Beach (CA), Bolsa Chica State Beach in Huntington Beach (CA), Newport Beach (CA), Ocean City (MD), Park Point - Community Club Beach in Duluth (MN) and Hampton Beach State Park in Hampton (NH). Some of the lowest ranking beaches (1-star) were Zach's Bay at Jones Beach State Park in Wantagh (NY), Ocean Beach Park in New London (CT), Venice Public Beach (FL) and Central Beach in Point Pleasant (NJ).

While the report found a 10 percent decrease in closing and advisory days at beaches nationwide from 2007, it reveals this drop was the result of dry conditions in many parts of the country and decreased funding for water monitoring in some states last year, rather than a sign of large-scale improvement. The decline follows two years of record-high closing and advisory days and the primary pollution source, stormwater runoff after heavy rains, continues to be a serious problem that has not been addressed.

"When the rains return," Stoner said, "so will pollution, forcing beaches to issue more closings and advisory days."

For the full report, go to www.nrdc.org/beaches.

For the first time, the Testing the Waters report this year explores the effects of climate change on beachwater quality, revealing that climate change is expected to make pollution worse. The combined effects of temperature increases, and more frequent and intense rainstorms, will lead to increased stormwater runoff, sewer pollution and disease-causing pathogens in nearby waterways. Specifically, climate change is anticipated to influence the presence of pathogens that cause stomach flu, diarrhea and neurological problems in America's beachwater.

Nationally, 7 percent of beachwater samples violated health standards - indicating the presence of human or animal waste - showing no improvement from 2007 or 2006. The highest level of contamination was found in the Great Lakes, where 13 percent of beachwater samples violated public health standards. In fact, from 2005-2008, the Great Lakes consistently tested the dirtiest, while the Southeast and Delmarva Peninsula proved relatively cleaner than other regions. States with the highest percentage of samples exceeding health standards in 2008 were Louisiana (29 percent), Ohio (19 percent), Indiana (18 percent) and Illinois (15 percent). Those with the lowest percent of water samples exceeding health standards last year were Delaware, New Hampshire and Virginia (all with 1 percent).

While there was an overall decrease in closing and advisory days from 2007 nationwide, from 22,571 to 20,341 days, regionally the picture varied. Dry conditions led to decreases in closings and advisories for 2008 in the Delmarva Peninsula (67 percent), Gulf of Mexico (39 percent), California and Hawaii (21 percent), and the Southeast (12 percent). Wetter than usual conditions, however, led to an increase in closing and advisory days in New England (64 percent) and the Great Lakes (13 percent).

Beachwater pollution makes swimmers vulnerable to a range of waterborne illnesses including stomach flu, skin rashes, pinkeye, ear, nose and throat problems, dysentery, hepatitis, respiratory ailments, neurological disorders and other serious health problems. For senior citizens, small children and people with weak immune systems, the results can be fatal.

"Nobody wants their trip to the beach to send them to the bathroom or, worse, the emergency room," said Stoner. "It is vitally important to remember that if it has recently rained - or you see or smell a pipe discharging onto the beach - keep your head above water or avoid swimming altogether."

The best way to protect swimmers from beachwater pollution is to prevent it. Federal, state and local governments can make this a priority by requiring better controls on stormwater and sewage, the two largest known sources of beachwater pollution. A key solution is to utilize low impact development techniques in communities to retain and filter rainwater where it falls, letting it soak back into the ground rather than running off into waterways. This includes strategically placed rain gardens in yards, tree boxes on city sidewalks, green roofs that use absorbent vegetation on top of buildings, and permeable pavement that allows water to penetrate the material, instead of asphalt or concrete.

The Clean Coastal Environment and Public Health Act pending in Congress would provide money for more beachwater sampling and require use of faster testing methods so people get timely information about whether it is safe to swim. Additionally, the American Clean Energy and Security Act (ACES) that recently passed the House of Representatives will help communities prepare for further impacts of climate change on coastal communities such as flooding, sea level rise, increased stormwater pollution and sewer overflows, in addition to capping global warming pollution.

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Korduroy.tv's free Alaia shaping classes with Jon Wegener courtesy of
the awesome folks at Patagonia Cardiff. We'll also have a special sneek
screening of the new film "Tom's Creation Plantation.

Text by The University of Rhode Island, Photo by NOAA



International news reports last week about scuba divers off San Diego being menaced by large numbers of Humboldt's or jumbo squid have raised the ire of University of Rhode Island biologist Brad Seibel. As a leading expert on the species who has dived with them several times, he calls the reports "alarmist" and says the squid's man-eating reputation is overblown.

For years Seibel has heard stories claiming that Humboldt squid will devour a dog in minutes and could kill or maim unsuspecting divers.

"Private dive companies in Mexico play up this myth by insisting that their customers wear body armor or dive in cages while diving in waters where the squid are found. Many also encourage the squid's aggressive behavior by chumming the waters. I didn't believe the hype, but there was still some doubt in my mind, so I was a little nervous getting into the water with them for the first time," Seibel said.

Scuba diving at night in the surface waters of the Gulf of California in 2007, Seibel scanned the depths with his flashlight and saw the shadows of Humboldt squid far in the distance. After he got up his nerve, he turned off the light. When he turned it back on again 30 seconds later, he was surrounded by what seemed like hundreds of the squid, many just five or six feet away from him. Most were in the three- to four-foot size range, while larger ones were sometimes visible in deeper waters. But the light appeared to frighten them, and they immediately dashed off to the periphery.

The URI researcher's dive was more than just a personal test. It was part of a scientific examination of the species some call "red devil" to learn more about their physiology, feeding behavior and swimming abilities.

Humboldt squid feed in surface waters at night, then retreat to great depths during daylight hours. "They spend the day 300 meters deep where oxygen levels are very low," Seibel said. "We wanted to know how they deal with so little oxygen."

Seibel said that while the squid are strong swimmers with a parrot-like beak that could inflict injury, man-eaters they are not. Unlike some large sharks that feed on large fish and marine mammals, jumbo squid use their numerous small, toothed suckers on their arms and tentacles to feed on small fish and plankton that are no more than a few centimeters in length.

The highlight of Seibel's research cruise with colleagues from the Monterey Bay Aquarium Research Institute was diving with the impressive animals. Other divers participating were Lloyd Trueblood of URI, Steve Haddock of MBARI, and Alison Sweeney of the University of California, Santa Barbara.

Seibel was surprised by the large number of squid he encountered, which made it easy to imagine how they could be potentially dangerous to anything swimming with them. Their large numbers also made Seibel somewhat pleased that they appeared frightened of his dive light. Yet he said the animals were also curious about other lights, like reflections off his metal equipment or a glow-in-the-dark tool that one squid briefly attacked.

"Based on the stories I had heard, I was expecting them to be very aggressive, so I was surprised at how timid they were. As soon as we turned on the lights, they were gone," he said. "I didn't get the sense that they saw the entire diver as a food item, but they were definitely going after pieces of our equipment."

According to Seibel, there have been many active discussions among biologists and the dive community about the safety of diving with Humboldt squid. As a result of his experience, the URI scientist is preparing a formal report with his recommendations for safely diving with the squid, including suggestions to always carry a back-up dive light and to be tethered to a boat. Any time humans enter the habitat of a large animal, there is potential for dangerous interactions, he said, so divers should use caution.

"However, I want to spread the word that they aren't the aggressive man-eaters as they have been portrayed," Seibel said.

Text and Photo by Leibniz Institute of Marine Sciences




The ice is melting, the sea level is rising and species are conquering new habitats. The warming of the world climate has many consequences. Researchers now report that climate change influences the size of aquatic organisms.

For a long time scientists have observed the biological consequences of global climate change. One of the most famous symptoms is the shift of habitats from the equator further north or further south. More recent studies show that not only the habitats but also the size of organisms is affected.

Dr. Martin Daufresne of the HYAX Lake Ecosystem Laboratory in Aix-en-Provence, France, as well as Prof. Ulrich Sommer and Dr. Kathrin Lengfellner of the Leibniz-Institute of Marine Sciences (IFM-GEOMAR) in Kiel have shown that global warming leads to reduced body size of organisms in the ocean and in freshwater. Very different organisms showed this tendency: bacteria, plankton-algae, zooplankton and fishes in the North and Baltic Sea and in French rivers.

Three mechanisms seem to play a role in this process.

• First: The proportion of smaller species grows.
• Second: The proportion of smaller individuals grows within one species.
• Third: The animals reach sexual maturity with smaller body size.

"This development affects the functioning of the whole eco-system: The
body size is decisive for what animals can eat and by whom they are
eaten. A shift to smaller species and individuals within the fish
population could lead to a reduction of zooplankton because small fish
will eat less fish and more zooplankton. This could pave the way fvor
massive and unpleasant algal blooms. Furthermore, with smaller fish the
economic value of fishery declines", explains Prof. Sommer.

The bacteria, algae and zooplankton were examined in experiments of Baltic Sea plankton as part of the German Research Foundation-programme AQUASHIFT. The results about fish size are based on long term measurements in the North Sea, the Baltic Sea and in French Rivers.