Tag Archives: Bluefin Tuna

FISHERIES: Federal fishery enforcement agents seize 881-pound bluefin tuna from commercial fishing vessel

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A fisherman’s enormous catch recently ignited a debate over whether fishers should be allowed to keep bycatch that is caught and landed without the proper permit, which would have allowed the fishing vessel to legally keep or sell the catch. Unfortunately, small-government advocates pounced and argued that the seizure was yet another example of federal government overreach and mismanagement. However, small-government advocates are either naive or are ignoring a plethora of facts and issues.

Basically, if commercial fishing vessels fish in state or U.S. federal government waters, then these fishing vessels are required to hold a permit. The permit allows the fishing vessels to use certain gear, in certain areas, to fish for, catch, land and sell certain species. For example, a fishing vessel with a groundfish permit to catch cod, haddock, and certain flounder species with a bottom trawl net can’t keep a bluefin tuna, an endangered, pelagic species, that is caught with the fishing vessel’s bottom trawl net — unless, for some reason, the permit authorizes the fishing vessel to keep the tuna. The purpose of utilizing permits is to control the number and types of fish caught in order to avoid overfishing and the economic collapse of fisheries.

Recently, a bottom trawler owned by Carlos Rafael landed a bluefin tuna weighing an incredible 881 pounds. However, since his fishing vessel’s permit didn’t allow him to keep the bluefin tuna, which was caught in his bottom trawl, the boat owner, unfortunately, had to surrender his tuna over to the feds. The commercial fishing vessel, apparently, did have a permit to keep a bluefin tuna caught and landed on a rod and reel.

Of course, debate ensued regarding whether the fishing vessel should have been forced to surrender its valuable catch, which was sold for “less than $5,000.” I believe that Monica Allen, the deputy director at NOAA Fisheries public affairs, put it best:

“We’re leaders among 45 countries in the conservation of this fish. Failure to enforce the regulations would damage our credibility internationally,” Allen said. There are not enough bluefin for those fishermen who target it as their sole focus, she added. “If trawl fishermen were allowed to keep bluefin, even when caught accidentally, that would create an incentive. If the stocks are rebuilt, this could actually become a way to catch them.”

Rafael, however, dismissed this logic out of hand. “That makes no sense, and I think that shows what they know about these fish,” he said.

Of course, seizing the bluefin tuna makes sense. If one fisher, who doesn’t have the proper permit, is allowed to keep a bluefin tuna, then more fishers would want to keep a tuna that was caught and landed without the proper permit. Furthermore, it would be a nightmare for enforcement and for efforts to conserve species that are severely depleted. Also, allowing a fisher to keep a tuna, if he or she doesn’t have the proper permit to do so, would make a mockery of the regulatory system. Obviously, such a move would also be unfair to fishers that have had their catches seized in the past or who have been fined in the past or who have had to discard bycatch overboard in the past.

No one, I imagine, wants to regulate commercial fishing, but the practice is inherently unsustainable, so regulations and plans are required. It’s true that there are many fishers that are conservation-minded, but it still takes cooperation between fishers, fishery managers, fishery observers, regulators (and regulation), and scientists to produce a sustainable fishery. No group can do it alone.

Sources:

  1. New Bedford fishermen snare giant tuna, feds take it
  2. Media hook onto boat owner after feds seize giant tuna

FISHERIES: NOAA to require weak hooks to reduce the bycatch of large bluefin tuna in the Gulf of Mexico

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Images: The first image shows, via the United Nations’ Fisheries and Aquaculture Department, a tuna longline. A yellowfin tuna is caught on a weak hook in the second image. Larger species are excluded, because the hooks “straighten when a large fish, such as bluefin tuna, is hooked, releasing it but holding on to smaller fish.” The image is via Mike Carde. Via NOAA, some weak hooks, at various stages of bending, are shown in the third image. The fourth image, via izik on Flickr, illustrates some longline hooks from an Alaskan fishery.


In a fishery, which can mean many things, fishers target certain species for personal consumption or for market. However, sometimes, fishers catch other species in addition to the species that they’re targeting. These non-target species are known as bycatch, and even though bycatch might be illegal to keep, to consume, to target, or to market, bycatch may still be incidentally caught in some fisheries.

Therefore, if the fisher doesn’t have a permit to keep certain species or if the species is illegal to keep, it’s simply wastefully discarded overboard. Bycatch isn’t wasted, however, if a fisheries observer is onboard to scientifically sample the species or if the fishers keep the specimen to turnover to scientists for research. As a result, bycatch can yield valuable data about a species and its interaction with commercial fishing gear.

Nonetheless, bycatch is a serious problem in some fisheries — particularly in some commercial fisheries, where the ecological footprint can be significant. Bycatch might include other species of fish, undersized or juvenile target species, marine mammals, sea turtles, sea birds, or invertebrates. Fisheries with little or no bycatch and minimal impact to the environment are often called clean fisheries. For example, “environmental seafood guides produced by Audubon and the Monterey Bay Aquarium have cited the Albacore troll fishery as an example of a clean fishery with little bycatch or impact on the environment.”

Due to being incidentally caught, some species, in particular, are at risk. For example, populations of endangered species, valuable species, or species that are easily caught as bycatch in certain fisheries suffer from illegal fishing or from fisheries that are inefficient or dirty. However, fisheries research can result in improvements that mitigate or even eliminate bycatch of certain species (thus making the fishery cleaner), so cooperative research is important in ensuring continued seafood production and in making fisheries more sustainable.

Big, fat female fish, which have a higher fecundity, and therefore are important to sustaining certain fish stocks or populations, are vulnerable as bycatch in some fisheries. The loss of important breeding individuals is devastating to certain fish stocks or to certain populations of fish species. One such fishery, which is problematic for incidentally removing important breeding individuals, is the surface-longline fishery. However, conservationists, fishery managers, and scientists are working to improve the fishery by tweaking fishing gear or utilizing bycatch reduction devices. Starting May 5, 2011, for example, “NOAA’s Fisheries Service will require commercial fishermen who fish for yellowfin tuna, swordfish and other species with longlines in the Gulf of Mexico to use a new type of hook, called a weak hook, designed to reduce the incidental catch of Atlantic bluefin tuna.” More via NOAA:

Directed fishing for bluefin tuna in the Gulf has been prohibited since the early 1980s, however bluefin are caught incidentally by longline fishermen who target other species. The Gulf of Mexico is the only known spawning area for the western stock of Atlantic bluefin tuna, a historically overfished species. Many bluefin die from the stress endured in this incidental capture in warm water even if fishermen release them.

“NOAA worked with longline fishermen from the Gulf to test the weak hook carefully over the last three years,” said Eric Schwaab, assistant NOAA administrator for NOAA’s Fisheries Service. “Our cooperative scientific research with fishermen is showing that this new technology can protect bluefin tuna in the Gulf while still allowing fishermen to target yellowfin tuna and swordfish.”

The weak hook is a circular hook constructed of thin gauge wire, and is designed to straighten when a large fish, such as bluefin tuna, is hooked, releasing it but holding on to smaller fish. The average size of bluefin tuna landed in the Gulf of Mexico longline fishery is 485 pounds, while the average for yellowfin tuna is about 86 pounds.

Yellowfin tuna and swordfish are valuable commercial fisheries in the Gulf of Mexico, supporting fishing jobs on approximately 50 vessels as well as jobs on shore. The two species bring longline fishermen annual dockside earnings of $7 million. Research showed that the weak hook could result in some reductions in target catch while some longline fishermen have reported weak hooks did not hurt their businesses.

“During our tests, we used regular hooks for half our hooks and half were the new weak hooks,” said Capt. Mike Carden, a longline fisherman from Panama City, Fla. who took part in the cooperative research. “We were so happy with the weak hooks we quit using the heavy hooks. The weak hook releases fish we don’t want to catch. Because it’s smaller and lighter, we catch more yellowfin tuna on the weak hook. There’s several of us who have gone to the weak hook.”

And from Dot Earth:

Federal fisheries officials, after field studies and public debate, have issued a new rule requiring commercial fishing boats deploying long lines of fish hooks in the Gulf of Mexico to use “weak hooks” that hold smaller, abundant species like yellowfin tuna but, in theory, will allow  depleted Atlantic bluefin tuna and other rare large species to escape. Here’s background in a news release from the National Oceanic and Atmospheric Administration.

.       .       .

The agency release included a supporting comment from a captain of one of the 50 or so commercial longline vessels in the fishery:

“During our tests, we used regular hooks for half our hooks and half were the new weak hooks,” said Capt. Mike Carden, a longline fisherman from Panama City, Fla., who took part in the cooperative research. “We were so happy with the weak hooks we quit using the heavy hooks. The weak hook releases fish we don’t want to catch. Because it’s smaller and lighter, we catch more yellowfin tuna on the weak hook. There’s several of us who have gone to the weak hook.”

The Pew Environmental Trusts, which has been tracking the issue closely, gave a very mixed review to the move. Here’s a statement e-mailed to me by Dave Bard, a spokesman, followed by a video the group has produced on bluefin and the gulf:

Pew is pleased that the National Marine Fisheries Service (NMFS) has recognized the major bycatch problem with bluefin tuna in the Gulf of Mexico, the fish’s only known spawning area in the western Atlantic Ocean. The agency has issued a short-term solution requiring the use of “weak” hooks starting May 5, 2011. Pew is also pleased that NMFS has left the door open to consider long-term solutions including time and area closures. But, a year-round prohibition on surface longlines is the only way to provide effective long-term protection for bluefin tuna and other rare and beautiful species in the Gulf. This prohibition would still allow fishermen in the Gulf to catch swordfish and yellowfin tuna; they would just be required to use more selective alternatives to wasteful surface longlines.

Here’s the video report:

You can continue reading more about this story at Dot Earth.

Online Resources:

  1. New Fishing Hooks Protect Bluefin Tuna in Gulf of Mexico But Allow Catch of Yellowfin Tuna and Swordfish
  2. Longline Gear Innovation
  3. Industrial Tuna Longlining
  4. WWF’s International Smart Gear Competition
  5. Stop Surface Longlining in the Gulf of Mexico
  6. Northeast Cooperative Fisheries Research
  7. Seafood Watch Program: A Consumer’s Guide to Sustainable Seafood

MERCURY POLLUTION: Federal government study finds that mercury contamination in fish widespread

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“No fish can escape mercury pollution.”

BREAK
Mercury Contamination In FishPeople depend on the environment for certain ecosystem services, such as harvesting food from the environment. As a result, mercury pollution is a public health threat, because when mercury accumulates in the environment, it contaminates ecosystems, so human food sources (e.g., fish) that depend on these ecosystems for survival are contaminated as well. Accordingly, when we harvest these foods, we contaminate our bodies with these toxins.

According to the National Atmospheric Deposition Program, “mercury is in a class of chemicals called persistent bioaccumulative toxins.” Consequently, mercury “persists in the environment for long periods by cycling back and forth between the air, water, and soil, all the while changing chemical forms, [so] . . . mercury never is removed from the environment: it just moves to other locations and eventually ends up in soils and sediments.”

There are three forms of atmospheric mercury: (1) elemental mercury (which accounts for about 95% of the total Hg in the atmosphere), (2) reactive gaseous mercury, and (3) particulate mercury. Anthropogenic sources of mercury are delivered into the environment through atmospheric deposition, and coal-fired power plants are significant contributors of mercury deposition. Once deposited into aquatic environments, bacterial activity transforms mercury into methylmercury.

BioaccumulationAccording to the United States Geological Survey (USGS), “methylmercury is an organic form of mercury that is produced largely as a byproduct of natural microbial processes, when inorganic mercury is present, [and] methylmercury is an extremely toxic form of mercury.” Methylmercury is extremely toxic, because it not only bioaccumulates or is magnified through the food chain, but it’s easily absorbed by living organisms.  Furthermore, methylmercury is considered a neurotoxin. In humans, fish and “seafood consumption is the main way methylmercury is taken up by humans.”

Humans aren’t the only living things impacted by mercury pollution, because other animals are certainly impacted by anthropogenic sources of mercury as well. According to EnergyWisePA.org, “Effects of methylmercury exposure on wildlife can include mortality (death), reduced fertility, slower growth and development and abnormal behavior that affect survival, depending on the level of exposure. In addition, research indicates that the endocrine system of fish, which plays an important role in fish development and reproduction, may be altered by the levels of methylmercury found in the environment.”

A recent government study found that mercury contamination in freshwater ecosystems is widespread. Furthermore, another government study determined how mercury is transformed into methylmercury in oceanic environments.  That study also projected that mercury contamination of oceanic environments will continue to increase.  Likewise, mercury contamination of freshwater ecosystems will increase.  The contamination of any type of aquatic ecosystem with anthropogenic sources of mercury negatively impacts public health and livelihoods, thus economic opportunities. Are coal-fired power plants and cheap energy worth suffering these impacts? More from the U.S. Department of the Interior:

WASHINGTON, D.C. – Scientists detected mercury contamination in every fish sampled in 291 streams across the country, according to a U.S. Geological Survey study released today.

About a quarter of these fish were found to contain mercury at levels exceeding the criterion for the protection of people who consume average amounts of fish, established by the U.S. Environmental Protection Agency. More than two-thirds of the fish exceeded the U.S. EPA level of concern for fish-eating mammals.

“This study shows just how widespread mercury pollution has become in our air, watersheds, and many of our fish in freshwater streams,” said Secretary of the Interior Ken Salazar. “This science sends a clear message that our country must continue to confront pollution, restore our nation’s waterways, and protect the public from potential health dangers.”

Some of the highest levels of mercury in fish were found in the tea-colored or “blackwater” streams in North and South Carolina, Georgia, Florida and Louisiana — areas associated with relatively undeveloped forested watersheds containing abundant wetlands compared to the rest of the country. High levels of mercury in fish also were found in relatively undeveloped watersheds in the Northeast and the Upper Midwest. Elevated levels are noted in areas of the Western United States affected by mining. Complete findings of the USGS report, as well as additional detailed studies in selected streams, are available online.

For a national listing of fish advisories from the Environmental Protection Agency, click here.

Mercury, a neurotoxin, is one of the most serious contaminants threatening our nation’s waters. The main source of mercury to natural waters is mercury that is emitted to the atmosphere and deposited onto watersheds by precipitation. However, atmospheric mercury alone does not explain contamination in fish in our nation’s streams. Naturally occurring watershed features, like wetlands and forests, can enhance the conversion of mercury to the toxic form, methylmercury. Methylmercury is readily taken up by aquatic organisms, resulting in contamination in fish.

“This study improves our understanding of where mercury ends up in fish in freshwater streams,” said USGS scientist Barbara Scudder. “The findings are critical for decision-makers to effectively manage mercury sources and to better anticipate concentrations of mercury and methylmercury in unstudied streams in comparable environmental settings.”

The USGS studied mercury contamination in fish, bed sediment and water from 291 streams across the nation, sampled from 1998 to 2005. Atmospheric mercury is the main source to most of these streams — coal-fired power plants are the largest source of mercury emissions in the United States — but 59 of the streams also were potentially affected by gold and mercury mining. Since USGS studies targeted specific sites and fish species, the findings may not be representative of mercury levels in all types of freshwater environments across the United States.

All 50 states have mercury monitoring programs, and 48 states issued fish-consumption advisories for mercury in 2006, the most recent year of national-scale reporting to the EPA. The EPA regulates mercury emissions to air, land and water. In February 2009, the EPA announced that it intends to control air emissions of mercury from coal-fired power plants by issuing a rule under the Clean Air Act.

For a podcast regarding today’s announcement, click here.

IMAGE: How mercury cycles through an aquatic ecosystem:
Mercury Cycling in an Aquatic Ecosystem

According to an abstract from the study:

Mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury (MeHg) bioaccumulation. Sampled settings include stream basins that were agricultural, urbanized, undeveloped (forested, grassland, shrubland, and wetland land cover), and mined (for gold and Hg). Each site was sampled one time during seasonal low flow. Predator fish were targeted for collection, and composited samples of fish (primarily skin-off fillets) were analyzed for total Hg (THg), as most of the Hg found in fish tissue (95–99 percent) is MeHg. Samples of bed sediment and stream water were analyzed for THg, MeHg, and characteristics thought to affect Hg methylation, such as loss-on-ignition (LOI, a measure of organic matter content) and acid-volatile sulfide in bed sediment, and pH, dissolved organic carbon (DOC), and dissolved sulfate in water. Fish-Hg concentrations at 27 percent of sampled sites exceeded the U.S. Environmental Protection Agency human-health criterion of 0.3 micrograms per gram wet weight. Exceedances were geographically widespread, although the study design targeted specific sites and fish species and sizes, so results do not represent a true nationwide percentage of exceedances. The highest THg concentrations in fish were from blackwater coastal-plain streams draining forests or wetlands in the eastern and southeastern United States, as well as from streams draining gold- or Hg-mined basins in the western United States (1.80 and 1.95 micrograms THg per gram wet weight, respectively). For unmined basins, length-normalized Hg concentrations in largemouth bass were significantly higher in fish from predominantly undeveloped or mixed-land-use basins compared to urban basins. Hg concentrations in largemouth bass from unmined basins were correlated positively with basin percentages of evergreen forest and also woody wetland, especially with increasing proximity of these two land-cover types to the sampling site; this underscores the greater likelihood for Hg bioaccumulation to occur in these types of settings. Increasing concentrations of MeHg in unfiltered stream water, and of bed-sediment MeHg normalized by LOI, and decreasing pH and dissolved sulfate were also important in explaining increasing Hg concentrations in largemouth bass. MeHg concentrations in bed sediment correlated positively with THg, LOI, and acid-volatile sulfide. Concentrations of MeHg in water correlated positively with DOC, ultraviolet absorbance, and THg in water, the percentage of MeHg in bed sediment, and the percentage of wetland in the basin.

Information about the images used in this blog post:

  1. The image showing a sign warning of mercury contamination in fish is copyright 2009 Chuck Seggelin/Sagewood Studios: www.sagewoodstudios.com.
  2. The bioaccumulation of Hg image was found here.
  3. The image showing how mercury cycles through an aquatic ecosystem was found here.

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FISHERIES: Growing demand for sushi is having a big impact on the bluefin population

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From CBSNews.com on YouTube:

Bob Simon gets a glimpse of an ancient tuna fishing method called “la mattanza” off the coast of Sardinia. The global demand of sushi-grade tuna is having a big impact on the local fishermen. (CBSNews.com)

On the Net: The King Of Sushi, Growing Demand For Sushi Is Having A Big Impact On The Bluefin Population – CBS News