Fish are expected to shrink in size by 20 to 30 per cent if ocean temperatures continue to climb due to climate change. A new study by researchers at the University of British Columbia provides a deeper explanation of why fish are expected to decline in size.
"Fish, as cold-blooded animals, cannot regulate their own body temperatures. When their waters get warmer, their metabolism accelerates and they need more oxygen to sustain their body functions," said William Cheung, co-author of the study, associate professor at the Institute for the Ocean and Fisheries and director of science for the Nippon Foundation-UBC Nereus Program. "There is a point where the gills cannot supply enough oxygen for a larger body, so the fish just stops growing larger."
Daniel Pauly, the study's lead author and principal investigator of the Sea Around Us at the Institute for the Ocean and Fisheries, explains that as fish grow into adulthood their demand for oxygen increases because their body mass becomes larger. However, the surface area of the gills -- where oxygen is obtained -- does not grow at the same pace as the rest of the body. He calls this set of principles that explains why fish are expected to shrink "gill-oxygen limitation theory."
For example, as a fish like cod increases its weight by 100 per cent, its gills only grow by 80 per cent or less. When understood in the context of climate change, this biological rule reinforces the prediction that fish will shrink and will be even smaller than thought in previous studies.
Warmer waters increase fish's need for oxygen but climate change will result in less oxygen in the oceans. This means that gills have less oxygen to supply to a body that already grows faster than them. The researchers say this forces fish to stop growing at a smaller size to be able to fulfill their needs with the little oxygen available to them.
Some species may be more affected by this combination of factors. Tuna, which are fast moving and require more energy and oxygen, may shrink even more when temperatures increase. Smaller fish will have an impact on fisheries production as well as the interaction between organisms in the ecosystems.
New study shows Shortfin mako shark fishing mortality rate is much higher than previously thought.
Shortfin mako shark in the north Atlantic at Condor Bank, Azores. Credit: Patrick Doll (CC 3.0)
More bad news for sharks. A new study using satellite tracking by researchers from Nova Southeastern University's Guy Harvey Research Institute (GHRI), the University of Rhode Island and other colleagues shows that the fishing mortality rate of the shortfin mako in the western North Atlantic is considerably higher than previously estimated from catches reported by fishermen. These data suggest that this major ocean apex predator is experiencing overfishing, raising serious concerns about whether the current levels of fishery catches in the North Atlantic are sustainable. The new study has been published in the Journal Proceedings of the Royal Society B.
"Traditionally, the data obtained to determine the rate of fishing mortality, a key parameter used to help gauge the health of shark stocks, has depended largely on fishermen self-reporting any mako sharks they may have caught," said Mahmood Shivji, Ph.D., senior author of the study and director of the NSU's GHRI. "The challenge is that not all fishermen report the same way or some may underreport or even not report their mako shark captures at all, so the these catch data are known to be of questionable reliability."
Shivji said that near real-time tracking of mako sharks using satellite tags and directly seeing how many were captured allowed researchers to bypass the dependency on self-reporting by fishermen.
"Using satellite tags for makos and possibly other fished species can be a time-efficient way and a fisheries-independent tool for gathering useful fisheries-interaction data, including answering fundamental questions about the levels of fishing survival and mortality," said Michael Byrne, Ph.D., the paper's lead author and postdoctoral fellow at NSU's GHRI when the study was done. "The tracking data also showed these mako sharks entered the management zones of 19 countries, underscoring how critical it is for countries to work together closely to manage and conserve these long-distance oceanic travelers." When the researchers began to gather, compile, disaggregate and review the data, the results were startling.
An unexpectedly high proportion, 30% of the 40 satellite tagged sharks, were captured in fisheries. After modelling the probability that a mako shark would survive a year without being captured (a 72% chance) and calculating the fishing mortality rates, researchers determined that the rate at which shortfin makos were being killed in fisheries was actually 10 times higher than previously believed.
"From a conservation and protection point of view, this is huge," said Bradley Wetherbee, Ph.D., a research scientist from the University of Rhode Island's Department of Biological Sciences and a member of NSU's GHRI. "It's vital that we have the most accurate data possible to aid decision-makers in managing marine life populations sustainably. If they have inaccurate information, it's much more difficult to make the correct decisions for properly managing populations. Everyone wants the populations managed in a sustainable way."
Globally, many shark species have seen significant declines in their numbers, with fisheries overexploitation cited as a major cause. This can happen in many ways -- some shark species are specifically targeted while others are captured by accident (called bycatch.) No matter how sharks are taken from the world's oceans, the fact remains that the current levels of removal for many species are unsustainable.
The researchers stress that the work they are doing has the goal of providing the most accurate information possible to those in positions to take action to manage mako and other shark species. They both say that the goal is create successful fisheries management and conservation - to avoid declining populations, and to do that, we must have as much accurate data as possible.
"We have to have sustainable approaches to fishing," Dr. Shivji said. "Sharks might get a bit of a bad rap in the media, but these apex predators are vital to the overall health of our oceans. You remove them from the equation and, quite honestly, we don't know how far those ripples will be felt. One thing we do know is it won't be inconsequential."
Aquacultures are polluting Chile's rivers with a cocktail of dissolved organic substances.
Salmon Farming, Chile. The waste water is conducted into the river through a pipe (center of picture). Credit: Norbert Kamjunke.
Salmon lead a fairly varied life. The adult fish live in the sea but swim upstream into rivers to reproduce and lay their eggs in gravel beds in the upper reaches. This is where the young hatch, grow for a while in the clean, oxygen-rich water, and then set off towards the sea. To breed the popular edible fish, farmers have to provide different living conditions depending on the age of the fish.
Chilean fish farmers base their approach on the natural life cycle of the salmon. In the clear rivers which flow from the central ridge of the Andes towards the Pacific, they have installed a few hundred hatcheries for the eggs and the youngest animals. Slightly larger salmon live in cages in the lakes of the South American country, and the adults then move into similar accommodation anchored in the sea just off the coast. In 2012, Chile's aquacultures used this method to produce some 820,000 tonnes of salmon with a total value of just under five billion US dollars. For years, the country has been ranked second behind Norway in the list of key salmon producers worldwide.
However, this has not been without an impact on the environment. The cages for the medium and larger fish leak excrement, food residue and other substances into the country's seas and coastal waters. The companies also draw water for their hatcheries from some of the extremely clean, natural rivers. They pump it through the tanks for the young salmon before reintroducing it to the river further downstream - where it is certainly not in good condition.
Rather than clear water, it is more like a fishy broth which flows downstream from this kind of facility - which is a burden for residents, tourists and aquatic organisms. "Completely turbid water is no longer allowed to re-enter the river," reports Dr Norbert Kamjunke, a biologist at UFZ. The number of particles contained in the water must be below certain limit values. The aquacultures are now using sedimentation tanks and rotary filters to clarify their waste water. However, there are no such regulations for dissolved substances which simply flow into the water as before without any treatment or monitoring. And in huge quantities.
In an earlier study, Norbert Kamjunke and his colleagues discovered that, in facilities of this kind, around 40 tonnes of dissolved organic substances end up in the rivers for every 50 tonnes of farmed salmon. These substances, which chemists group together as Dissolved Organic Matter (DOM), include the liquid excretions from the salmon, and dissolved residues of food and excrement. "It also contains disinfectants and antibiotics," he explains. But what compounds does this cocktail contain exactly? And what impact does it have on the water? Researchers have recently investigated this in detail for the first time.
To do so, they used state-of-the-art methods of chemical analysis. Using fluorescence measurements, high-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy, the researchers studied the waste water from four Chilean aquacultures and samples taken from sections of the river both upstream and downstream of the farms. They worked with colleagues from the Universidad Austral de Chile in Valdivia to take samples, with the subsequent measurements carried out at the Helmholtz Centre in Munich. "We were able to determine exactly what DOM molecules were present in the water and in what concentration," explains Norbert Kamjunke.
The investigation showed that each of the rivers naturally has a slightly different chemical fingerprint. If it flows through heavily forested areas, the water will contain a large amount of humic matter. By contrast, water in volcanic regions tends to have a high proportion of sulphur compounds. However, there are also similarities. Natural sections of river generally contain less dissolved organic material. And this limited load consists of compounds which are difficult for bacteria to break down. "Those areas are predominantly low in nutrients," summarises Norbert Kamjunke.
However, the picture changes when waste water from aquaculture is introduced. These facilities release large quantities of readily biodegradable compounds. In particular, much higher concentrations of carbohydrates, proteins and their building blocks, and lipids are present downstream of the facilities. The aquacultures therefore provide the low-nutrient rivers with a kind of fertilizer boost.
But what does this entail for the water and its inhabitants? The researchers also investigated this issue in their study. They used laser scanning microscopes to examine the slippery film that grows on stones on the river bed. Upstream of the aquacultures, these biofilms contained a large amount of microscopic algae. These organisms were much less abundant downstream, where there were many more bacteria. "But this changes the entire ecosystem," explains Norbert Kamjunke.
The algae on the bottom of the natural waters play a key role for several reasons. Firstly they produce oxygen, and secondly they provide food for countless minute grazing organisms. Gastropods, mayfly and stone fly larvae all graze this film. And they in turn are eaten by fish. "The basis of the entire food web would disappear if this algae didn't exist," explains Norbert Kamjunke. But this is not the only way in which the waste water from the aquacultures alters living conditions in the river. The bacteria downstream of the facilities use up a large amount of oxygen to break down the dissolved organic matter. Excessively low oxygen concentrations can spell the end of many species which have adapted to life in clean flowing water.
However, the high level of bacterial activity that the team measured downstream of the salmon hatcheries also cleans the water. "Nevertheless, rivers should not be misused as natural sewage treatment plants," emphasises Norbert Kamjunke. For one thing, clean and unpolluted waters and their inhabitants deserve special protection. For another thing, the water downstream of the facilities has to flow quite a distance downstream until it is clean again. The length of this stretch depends on the external circumstances. The miniature water purifiers work most effectively at high temperatures and low flow rates. An earlier study by researchers from Magdeburg showed that the bacteria had broken down the pollution around 2.7 kilometres downstream of the facility. "In winter, however, they need a much longer section of river," says Norbert Kamjunke. And this is not always available to them in the short rivers of the Andes.
The researchers therefore advocate the introduction of limit values for the DOM concentrations entering the river. Their findings in relation to the activities of the bacteria could help to specify these values in order to avoid overloading the river. The aquacultures would then have to clean their waste water more effectively before re-introducing it to the river - for example using biological filters. In principle, these are large pipes filled with stones on which biofilm grows. The waste water enters at the top and leaves at the bottom, having been clarified by the bacteria in between. "Our results also show how large these facilities would have to be," explains Norbert Kamjunke. The measured degradation rates can be used to calculate how much stone surface area is required for the desired purification efficiency.
The researchers also draw another conclusion from their study. They do not consider it advisable to install any further aquacultures on Chilean rivers. The authorities have already imposed a moratorium on new salmon farms in the country's lakes. Operators are now considering the option of moving the farming of medium-sized salmon from the lakes to the rivers. "In theory that could work," believes Norbert Kamjunke. "But from an ecological perspective, it would not be a good idea."
The research, carried out by scientists at the University of Zurich and University of Tasmania, used detailed records collected during the commercial whaling of the 20th century and collated by the International Whaling Committee (IWC) - to look at the effects of overharvesting on whale populations, and used this historic data to help develop methods which can be applied to species of current conservation concern.
Overfishing is a threat faced by many marine species, and is a problem that is likely to get worse with an increasing human population. Overfishing can lead to the collapse of fish stocks, which can take many decades to recover, if they do at all. A classic example of this is the overharvesting of whales for blubber, oil and meat during the 20th century, where large collapses in the numbers of whales occurred after decades of overharvesting.
Warning signs detectable long before collapse
Previous work on experimental systems has suggested that extreme shifts in the average body size of a population, along with fluctuations in the number of individuals, can be indicative of an approaching collapse; however this had never been demonstrated in a wild population before. The team lead by ecologist Christopher Clements from the University of Zurich analysed data on the number and size of whales harvested from 1900 onwards to see whether these tell-tale shifts in body size and fluctuations in the numbers were present before the documented collapse of whale populations. "We looked at data on blue, fin, sei and sperm whales and found significant declines in body size, with sperm whales taken in the 1980s four metres shorter on average than those in 1905", Christopher Clements explains. "This means that warning signals were detectable up to 40 years before a population collapse".
Using technique for species of conservation concern
These results suggest that tracking changes in the mean body size might help to predict when populations are at risk of collapsing. "Our technique could be used to help provide other species of conservation concern. Moreover, it could allow interventions to be put in place to stop this happening", says Christopher Clements.
Global marine fisheries discards: A synthesis of reconstructed data by the Sea Around Us. Credit: UBC.
Industrial fishing fleets dump nearly 10 million tonnes of good fish back into the ocean every year, according to new research.
The study by researchers with Sea Around Us, an initiative at the University of British Columbia's Institute for the Oceans and Fisheries and the University of Western Australia, reveals that almost 10 per cent of the world's total catch in the last decade was discarded due to poor fishing practices and inadequate management. This is equivalent to throwing back enough fish to fill about 4,500 Olympic sized swimming pools every year.
"In the current era of increasing food insecurity and human nutritional health concerns, these findings are important," said Dirk Zeller, lead author for the study who is now a professor at the University of Western Australia and senior research partner with the Sea Around Us. "The discarded fish could have been put to better use."
Fishers discard a portion of their catch because fishing practices damage the fish and make them unmarketable, the fish are too small, the species is out of season, only part of the fish needs to be harvested--as with the Alaska pollock roe--or the fishers caught species that they were not targeting, something known as bycatch.
"Discards also happen because of a nasty practice known as high-grading where fishers continue fishing even after they've caught fish that they can sell," said Zeller. "If they catch bigger fish, they throw away the smaller ones; they usually can't keep both loads because they run out of freezer space or go over their quota."
The study examined the amount of discarded fish over time. In the 1950s, about five million tonnes of fish were discarded every year, in the 1980s that figure grew to 18 million tonnes. It decreased to the current levels of nearly 10 million tonnes per year over the past decade.
The decline in discards in recent years could be attributed to improved fisheries management and new technology, but Zeller and his colleagues say it's likely also an indicator of depleted fish stocks. As the Sea Around Us' 2016 global catch reconstruction paper revealed, catches have been declining at a rate of 1.2 million tonnes of fish every year since the mid-1990s.
"Discards are now declining because we have already fished these species down so much that fishing operations are catching less and less each year, and therefore there's less for them to throw away," he said.
Zeller and his colleagues Tim Cashion, Maria Palomares and Daniel Pauly, say that the study also shows how industrial fleets move to new waters once certain fisheries decline.
"The shift of discards from Atlantic to Pacific waters shows a dangerous trend in fisheries of exporting our fishing needs and fishing problems to new areas," Cashion said.
Marine seismic surveys used in petroleum exploration could cause a two to three-fold increase in mortality of adult and larval zooplankton, new research published in leading science journal Nature Ecology and Evolution has found.
Scientists from IMAS and the Centre for Marine Science and Technology (CMST) at Curtin University studied the impact of commercial seismic surveys on zooplankton populations by carrying out tests using seismic air guns in the ocean off Southern Tasmania. The research found that the air gun signals, commonly used in marine petroleum exploration, had significant negative impact on the target species, causing an increase in mortality from 18 per cent to 40-60 per cent. Impacts were observed out to the maximum 1.2 kilometre range tested, 100 times greater than the previously assumed impact range of 10 metres, and all larval krill in the range were killed after the air gun's passage.
Lead author, Curtin University and CMST Associate Professor Robert McCauley, said the results raise questions about the impact of seismic testing on zooplankton and the ocean's ecosystems more widely.
"Zooplankton underpin the health and productivity of global marine ecosystems and what this research has shown is that commercial seismic surveys could cause significant disruption to their population levels," Associate Professor McCauley said.
The study, jointly funded by Curtin University and the University of Tasmania, involved two replicated experiments carried out on consecutive days using a 1.6km survey line in Storm Bay, southern Tasmania.
IMAS Associate Professor and research co-author Jayson Semmens said a series of sonar lines run perpendicular to the air gun line were monitored prior to, and immediately after the air gun run.
"These sonar runs 'imaged' the zooplankton, and showed a lowered zooplankton presence starting 15 minutes after the air gun passed, with a large 'hole' in the zooplankton evident 30 minutes after the air gun pass," Associate Professor Jayson Semmens said.
This 'hole' or region of lowered zooplankton presence was symmetric about the air gun line and increased through time.
The abundance levels of living and deceased zooplankton were also tested in the same area, before and after the seismic survey testing.
"We counted the number of live and dead zooplankton collected in nets using a special staining technique and found that two to three times as many zooplankton were dead following the air gun operations than those collected before," Associate Professor Semmens said.
Associate Professor McCauley said he hoped the research would prove useful in assisting regulatory authorities to monitor and manage marine seismic survey operations, in understanding how these surveys impact marine systems and how we may reduce such impacts.
"Plankton underpin whole ocean productivity," Associate Professor McCauley said. "Their presence impacts right across the health of the ecosystem so it's important we pay attention to their future."
The first public sharing of government data marks a victory for transparency in an opaque industry where research and sustainable management have suffered from a lack of information on where fishing happens and how fishers interact with ocean resources.
Fishing boat in Sumatra, Indonesia. Credit: James Gagen (CC 2.0).
This week, at the United Nation's Ocean Conference, the Republic of Indonesia becomes the first nation ever to publish Vessel Monitoring System (VMS) data revealing the location and activity of its commercial fishing fleet. The new data being made public on the Global Fishing Watch public mapping platform reveals commercial fishing in Indonesian waters and areas of the Indian Ocean where it had previously been invisible to the public and other nations.
Susi Pudjiastuti, the Minister of Fisheries and Marine Affairs for the Republic of Indonesia, is taking a bold step toward increasing transparency in her country's fishing industry. Today she urges other nations to do the same.
"Illegal fishing is an international problem, and countering it requires cross border cooperation between countries," says Minister Susi. "I urge all nations to join me in sharing their vessel monitoring data with Global Fishing Watch. Together, we can begin a new era in transparency to end illegal and unreported fishing."
Also at the UN Ocean's Conference, Global Fishing Watch has committed to host any country's VMS data, calling on other governments to follow Indonesia's lead. "We believe publicly shared VMS will become a powerful new standard for transparent operation in commercial fishing," says Paul Woods, Global Fishing Watch CEO and Chief Technology Officer for SkyTruth, a founding partner of Global Fishing Watch along with Oceana and Google. "SkyTruth has been collaborating with the Indonesian government for the past two years to really understand their VMS data and find new ways for VMS to enhance their fisheries management."
Working closely with Oceana toward a united goal of transparency at sea, Peru becomes the first nation to follow Indonesia's lead. Vice Minister for Fisheries and Aquaculture, Hector Soldi, announced Peru's intent to publicly share their VMS data in Global Fishing Watch.
"We applaud the commitments made by Peru and Indonesia to publish their previously private vessel tracking data and encourage other countries to follow their lead," said Jacqueline Savitz, Senior Vice President for the United States and Global Fishing Watch at Oceana. "Together, with forward-thinking governments like these, we can bring even greater transparency to the oceans. By publishing fishing data and using Global Fishing Watch, governments and citizens can unite to help combat illegal fishing worldwide. With more eyes on the ocean, there are fewer places for illegal fishers to hide."
Global Fishing Watch uses publicly broadcast Automatic Identification System (AIS) signals from ships at sea to reveal the activity of the majority of all industrial-sized commercial fishing vessels (those exceeding a capacity of 100 Gross Tons which average around 24 meters). The inclusion of government-owned VMS data adds detailed information on smaller commercial fishing vessels that are not required to carry AIS, and are therefore not reliably trackable by any other means. Indonesian regulations require VMS on fishing vessels with a capacity equal to or exceeding 30 Gross Tons (averaging about 16 meters or more). Indonesia is the second-largest producer of wild-caught seafood in the world, and Indonesian VMS alone adds nearly 5,000 fishing vessels to Global Fishing Watch's existing database of 60,000 vessels. "It's remarkable to see how adding in all these medium sized vessels with VMS really fills in the picture for large chunks of the ocean where we knew there was fishing, but just couldn't see it with AIS alone," says Woods. "It is also revealing new areas where we weren't aware fishing occurs."
Google's lead on Global Fishing Watch, Brian Sullivan, says that the platform is built using the latest cloud and machine learning technologies and can easily incorporate additional data sources or methodologies. "The ability to scale rapidly as new countries and providers join means we can move from raw data to quickly producing dynamic visualizations and reporting that promote scientific discovery and support policies for better fishery management," he said. "With Indonesia and Peru, two of the world's top five fishing nations, committed to a new age of transparency in the fishing industry, Google is committed to fostering international cooperation."
Because fishing occurs over the horizon and out of sight, the industry remains one of the most opaque in the world. The lack of knowledge about how much fish is being taken from the ocean, and who is fishing where severely hinders effective management. It also facilitates rampant Illegal, Unreported and Unregulated (IUU) fishing that threatens fish stocks, food security and the economies of coastal nations that depend on seafood for food, jobs and foreign export dollars.
Gains in transparency through the sharing of government VMS data will not only curb IUU, but will benefit the fishing industry as public demand for information about the source of their seafood increases and open data sharing through Global Fishing Watch provides validation of product source. These partnerships with Indonesia and Peru set a new bar for transparency at sea. Making this data publicly available will support regional cooperation in monitoring, surveillance and enforcement, reduce opportunities for corruption, and enable more informed management decisions.
In addition to committing to support any nation willing to share its VMS data publicly, Global Fishing Watch joined 50 members of the tuna industry and 17 other civil society organization to endorse the World Economic Forum Tuna Traceability 2020 Declaration made at the UN Oceans Conference.
*SkyTruth's work with the Indonesian Ministry of Fisheries and Marine Affairs has been made possible through support from the Packard Foundation and the Walton Family Fund. Global Fishing Watch is an independent 501c3 that was founded and supported by Oceana, SkyTruth and Google.
Oceana:
Oceana is the largest international advocacy organization dedicated solely to ocean conservation. Oceana is rebuilding abundant and biodiverse oceans by winning science-based policies in countries that control one third of the world's wild fish catch. With over 100 victories that stop overfishing, habitat destruction, pollution and killing of threatened species like turtles and sharks, Oceana's campaigns are delivering results. A restored ocean means that one billion people can enjoy a healthy seafood meal, every day, forever. Together, we can save the oceans and help feed the world.
SkyTruth:
SkyTruth is a nonprofit organization using remote sensing and digital mapping to create stunning images that expose the environmental impact of natural resource extraction and other human activities. We use satellite imagery and geospatial data to create compelling and scientifically credible visuals and resources to inform environmental advocates, policy-makers, the media, and the public.
Google:
Google Earth Outreach is a team dedicated to leveraging and developing Google's infrastructure to address environmental and humanitarian issues through partnerships with non-profits, educational institutions, and research groups.
Authored by a team from Conservation International, the University of Washington and other organizations, the paper is the first integrated approach to meeting this global challenge and will be presented as part of the UN Oceans Conference and the Seafood Summit, which both take place June 5-9 in New York and Seattle, respectively.
The article, published June 1 in Science, is in direct response to investigative reports by the Associated Press, the Guardian, The New York Times and other media outlets that uncovered glaring human rights violations on fishing vessels. The investigations tracked the widespread use of slave labor in Southeast Asia and its role in bringing seafood to American restaurants and supermarkets, chronicling the plight of fishermen tricked and trapped into working 22-hour days, often without pay and while enduring abuse. Subsequent investigations have documented the global extent of these abuses in a wide array of countries.
"The scientific community has not kept pace with concerns for social issues in the seafood sector," said lead author Jack Kittinger, Conservation International's senior director for global fisheries and aquaculture. "The purpose of this initiative is to ensure that governments, businesses, and nonprofits are working together to improve human rights, equality and food and livelihood security. This is a holistic and comprehensive approach that establishes a global standard to address these social challenges."
The paper identifies three key principles that together establish a global standard for social responsibility in the seafood sector: protecting human rights, dignity and respecting access to resources; ensuring equality and equitable opportunities to benefit; and improving food and livelihood security.
"This paper stresses that if we are serious about social responsibility in our food systems, we need to go beyond dealing with the 'worst-case' headlines of 'slavery at sea,'" said co-author Edward Allison, a UW professor in the School of Marine and Environmental Affairs.
Fishing boat heading out to sea on the Andaman coast of Thailand.Photo by Nathan Bennett.
"We argue that committing to sustainable seafood sourcing and supply is also about ensuring people who work in the food business - whether as harvesters or processors and packers - have decent work. It is also about ensuring communities who rely on the sea economically and culturally, particularly coastal indigenous communities, don't have their harvest rights appropriated by powerful outside interests."
More than half of the world's fisheries sector workforce is female, and there are still widespread gender-based disparities in income and working conditions, Allison added.
Seafood is the world's most internationally traded food commodity. By 2030, the oceans will need to supply more than 150 million metric tons of seafood to meet the demands of a growing population. The paper calls on governments, businesses and the scientific community to take measurable steps to ensure seafood is sourced without harm to the environment and people that work in the seafood industry.
"In some places, commercial fishing boats from other parts of the world are virtually robbing local small-scale fishers of the fish that they rely on to make a living and survive. Fisheries are not truly sustainable unless local people are able to benefit from the harvesting of resources," said co-author Nathan Bennett, a postdoctoral researcher at the UW.
As part of the initiative, Conservation International has organized a volunteer commitment, calling on governments, NGOs, businesses and other organizations to improve social responsibility in the seafood sector.
With climate change and social inequity addressed, restoring the ocean will help alleviate poverty, provide livelihoods, and improve the health of millions around the world. Credit: Lindsay Lafreniere.
A healthy ocean will benefit global sustainable development in a number of ways, finds a new report published today by the Nippon Foundation-Nereus Program. With climate change and social inequity addressed, restoring the ocean will help alleviate poverty, provide livelihoods, and improve the health of millions around the world.
"The challenges--both environmental and socioeconomic--that confront our oceans have reached a critical level," said Yoshitaka Ota, Nippon Foundation-Nereus Program Director of Policy. "This report demonstrates how ocean sustainability holds the key not only to our future prosperity but also for our survival from a comprehensive science-based perspective."
Developed in preparation for the UN World Ocean Conference, June 5 to 9, this is the first comprehensive report on Sustainable Development Goal 14: Life Below Water. The goal outlines seven targets agreed upon by the international community as key to the issues plaguing our oceans - from eliminating subsidies to minimizing acidification, ending overfishing to creating marine reserves.
"If fish stocks recover and are effectively managed, fisheries are more likely to provide sustainable livelihoods and food, and be more resilient to climate change" said William Cheung, Nippon Foundation-Nereus Program Director of Science. "Sustainable fisheries can help reduce poverty, limit hunger, and contribute to decent work and sustained economic growth by providing employment opportunities and productive fish stocks."
The Nippon Foundation-Nereus Program highlighted linkages between the ocean goal and the other 16 Sustainable Development Goals, developed by the UN in 2015. The report focuses on the challenges of climate change and social equity concerns in achieving ocean sustainability.
Credit: Lindsay Lafreniere.
"Climate change and social equity issues go hand and hand. The countries that are projected to be the hardest hit are tropical countries, which are mostly developing," said Gerald Singh, Nippon Foundation-Nereus Program Senior Fellow at UBC. "Sea levels are rising and fish are moving to different locations. But populations are also growing and moving towards coasts. Reducing inequalities is at the heart of sustainable development."
The co-benefits of achieving the ocean goal on the other sustainable development goals are wide reaching and not immediately apparent.
"The results may seem surprising, but a healthy ocean can contribute to achieving gender equality," said Ota. "Fisheries activities are quite gendered -- women typically do unrecognized and unrewarded work. Men will go on boats to capture fish that are sent to markets. But women are often collecting the subsistence food."
"A healthy ocean can also mean the difference between malnourishment and a steady supply of high quality protein for vulnerable communities," said Andrés Cisneros-Montemayor, Nippon Foundation-Nereus Program Manager. "The oceans are connected to our lives in many ways. Restoring the oceans isn't just an environmentalist's dream but is vital for employment, well being, livelihoods, and health around the world."
Changes impact local fishing communities, resource management.
Credit: IUCN
Scientists using a high-resolution global climate model and historical observations of species distributions on the Northeast U.S. Shelf have found that commercially important species will continue to shift their distribution as ocean waters warm two to three times faster than the global average through the end of this century. Projected increases in surface to bottom waters of 6.6 to 9 degrees F (3.7 to 5.0 degrees Celsius) from current conditions are expected.
The findings, reported in Progress in Oceanography, suggest ocean temperature will continue to play a major role in where commercially and recreationally important species will find suitable habitat. Sea surface temperatures in the Gulf of Maine have warmed faster than 99 percent of the global ocean over the past decade. Northward shifts of many species are already happening, with major changes expected in the complex of species occurring in different regions on the shelf, and shifts from one management jurisdiction to another. These changes will directly affect fishing communities, as species now landed at those ports move out of range, and new species move in.
"Species that are currently found in the Mid-Atlantic Bight and on Georges Bank may have enough suitable habitat in the future because they can shift northward as temperatures increase," said lead author Kristin Kleisner, formerly of the Northeast Fisheries Science Center (NEFSC)'s Ecosystems Dynamics and Assessment Branch and now a senior scientist at the Environmental Defense Fund. "Species concentrated in the Gulf of Maine, where species have shifted to deeper water rather than northward, may be more likely to experience a significant decline in suitable habitat and move out of the region altogether."
The researchers used bottom trawl survey data collected between 1968 and 2013 on the shelf to estimate niches for 58 demersal and pelagic species. A high-resolution global climate model known as CM2.6, developed by the NOAA Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton, New Jersey, was used to generate projections of future surface and bottom ocean temperatures across the region. The future temperatures were then used to project where marine species would find suitable habitat.
"Similar studies in the past used a coarse model with a roughly 100-kilometer or 62-mile ocean resolution, while the new model has a 10-kilometer or 6.2-mile ocean resolution, making the simulation of oceanic and atmospheric features much more accurate," said Vincent Saba of the NEFSC's Ecosystems Dynamics and Assessment Branch, who works at GFDL and is a co-author of the study.
Saba has compared the difference between the coarse model and the new high-resolution model as being similar to the difference between an old standard definition television set and today's ultra high definition screens.
Researchers looked at species distributions in spring and fall in the Gulf of Maine on the northern part of the Northeast Shelf and those on the southern end, from Georges Bank to the Mid-Atlantic Bight. They also examined what the shifting distributions might mean for fishing communities by looking at the current and potential future distance between the main fishing port in each state and the center of the distribution of suitable thermal area for the top-landed species by weight in each state.
Key northern species including Acadian redfish, American plaice, Atlantic cod, haddock, and thorny skate may lose thermal habitat, while spiny dogfish and American lobster may gain. Projected ocean warming in the Gulf of Maine may create beneficial conditions for American lobster populations, and they may continue to be accessible to fishing ports in the region.
In contrast, species like monkfish, witch flounder, white hake and sea scallops may remain accessible to major local fishing ports but could experience strong declines in habitat due to ocean warming. Atlantic cod, which is at the southern end of its range, may find suitable thermal habitat off the shelf entirely or in more northern waters in Canada.
In states south of New York, the distance to the centers of species distribution from ports may increase for some species, including summer flounder, which is currently the third most-landed species in Virginia. In North Carolina, the distance from ports to the center of distribution may increase for all six of the top landed species. Among the top six species landed in Virginia, only Atlantic croaker and striped bass are projected to have more suitable habitat.
"Warming waters may have a positive effect on smooth dogfish, Atlantic croaker, and striped bass in the southern part of the Northeast Shelf, with increases in suitable habitat in terms of area and species abundance, " Kleisner said. "But these species are also shifting northward and the bulk of the biomass of some species may be further from the main ports in southern states, making it more costly for fishermen to access these species. Conversely, as species move into new regions, fishermen may have new opportunities."
The projections indicate that as species shift from one management jurisdiction to another, or span state and federal jurisdictions, increased collaboration among management groups will be needed to set quotas and establish allocations.
"These changes will depend on the pace of climate change and on the ability of species to adapt or shift elsewhere to maintain a preferred habitat," said Kleisner. "We did not examine fishing pressure, species interactions and other factors that may influence future distributions. However, given the historical changes observed on the Northeast Shelf over the past five decades and confidence in the projection of continued ocean warming in the region, it is likely there will be major changes within this ecosystem."
"Those changes will result in ecological, economic, social, and natural resource management challenges throughout the region," Kleisner said. "It is important to understand large-scale patterns in these changes so that we can plan for and mitigate adverse effects as much as possible."
