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Bottom-Trawling Still Badly Regulated

Monday, May 20th, 2013

Is there any more damaging fishing method than bottom-trawling - dragging a heavy net along the seabed? Well, probably dynamiting and poisoning reefs are worse, but at least those methods have been banned.

A demersal or bottom-trawler drags a large net indiscriminately along the bottom seascape (saveourseas.org)

Even in the 1800s trawlers were aware that they were causing huge fish declines. Bottom-trawling spread around Britain from the 1820s, and as fish declined in numbers the inshore trawlers had to travel greater distances and increase their gear size to maintain their catch. By the 1880s they were calling for closing territorial waters to protect nursery and spawning grounds. However, the Royal Commission reports of 1866 and 1887 either disbelieved the fishermen, or simply failed to recommend restrictions. A model for the future.

Trawlers off the coast of Louisiana leave little of the bottom substrate untrawled (Wikipedia.org)

Bottom trawling of course spread around the world, leaving no suitable coast untouched. As inshore fisheries declined and EEZ limits extended to 200 miles, off-shore and deeper-water trawling continued to grow. When sea mounts were discovered and mapped, trawlers extended their reach to depths of 1500 meters. Such deep-water trawling continues, with an impact that is surely devastating though largely unknown.

The damage left by the pass of a single trawler through grass beds (oceana.org)

And yet everyone knows the problems associated with bottom-trawling, whether inshore or deep-water. It ploughs the bottom, removing its sediment, smoothing, radically changing the bottom seascape. It destroys ecosystems through the direct damage of the net, otter-boards and rock-hopper gear. It destroys ecosystems though its destruction and capture of non-target species. It decimates populations of target species through non-selective capture.

Bottom trawlers smooth out the seascape, changing the ecosystem (scientificamerican.com)

What can be done? Well, enter the Marine Stewardship Council. You are probably familiar with it, or at least with its blue logo indicating a fishery it has certified as sustainable. MSC was created in London in 1997, a joint effort of WWF and Unilever. In 1999 it became an independent non-profit organization.

Marine Stewardship Logo, promising the consumer a clear conscience (MSC.org)

Its rules for certification include the following: For a fisheries to be certified, fishing must continue indefinitely without over-exploiting resources. Productivity of the ecosystem must be preserved. All local, national and international laws must be upheld. And every company in the chain from boat to plate must be certified.

Between 2000 and 2004, MSC certified six fisheries, and the commercial benefits of certification began to be recognized. In 2006 WalMart announced that all fish it sold would be MSC certified by 2010. Whole Foods Market has gone the same route. So has Sainsbury’s, and Costco.

What better way to control, restrict, even prohibit bottom-trawling, which in no way meets the essential criteria required for certification? This looked very promising.

Instead, MSC began to certify bottom-trawled fisheries, mostly since 2011. Now certified are the fisheries for North Sea plaice, cod, haddock, and sole; New Zealand Blue whiting; Alaskan pollock in the Eastern Bering Sea (the largest single trawled fishery); and South African Hake, Barents Sea cod and haddock, Baltic cod, Iceland cod, North-west Atlantic shrimp and haddock. Others are in the pipeline.

Crew members opening a zipper in the net full of Alaskan Pollock on the F/V Ocean Hope 3 trawler. This fishery has been certified by MSC, but it shouldn’t be (alaska-in-pictures.com)

In 2011 National WWFs furiously denounced placing any bottom-trawled fish on the MSC list. Remember WWF helped found MSC in the first place. Greenpeace has also denounced it, as has the Pew environmental Group. And so have some of the very fisheries scientists who helped create the MSC.

MSC disagrees, as it proceeds to certify its 200th fisheries. But clearly it has radically loosened its rules for certification. One might be forgiven for thinking that once again the market place sets the rules instead of conservation.

We have not come very far from those disappointing Royal Commissions of 150 and 130 years ago.

There simply is no acceptable justification for bottom trawling. And MSC has failed us.

Belize has banned all bottom trawling within its 200 mile EEZ, a rare exception (uncharteredatolls.com)

Tags: archival records of bottom trawling, bottom trawling, Marine Stewardship Council, MSC
Posted in Marine Conservation, Sustainable fisheries | No Comments »

Culling Seals

Wednesday, April 24th, 2013

Cape Fur Seals breed on the coast of Namibia, where the annual ‘hunt’ removes about 90,000 seals, most of them pups (africareview.com)

The Canadian government has approved a cull of 70,000 grey seals over the next four years to protect cod (guardian.co.uk)

Seals of course eat fish. As opportunistic feeders, they’ll eat any fish they can catch.

When those fish decline in numbers or fail to recover when fishing is curtailed, a natural response has been to blame the seals.

Culling seals to protect fish populations of interest to human fishermen has been going on for more than a hundred years – California Sea Lions, Ringed and Grey Seals in the Baltic Sea, Harbor Seals in both BC and along US East Coast, Grey Seals on the US East Coast, Iceland, Norway, and the UK, and currently Cape Fur Seals in Namibia. In all cases seal populations experienced huge declines.

Culling, as opposed to harvesting, refers to killing the seals without intent to market them in some way. Though the market for seal parts is now close to non-existent, Canada considers its annual Harp Seal hunt to be harvesting, not culling.

Grey Seals on Sable Island: are they really responsible for failure of cod to recover? (truenorthimages.com)

Grey seals on Sable Island: are they really responsible for the failure of cod to recover? (truenorthimages.com)

But have the culls resulted in increased fish stocks for human fishermen? Oddly enough, nobody actually knows! There simply are no data, no experiments, nothing to indicate whether culling is effective or not. If anything, almost all of the examples suggest that no particular impact occurred on the target fish species.

Is there then any evidence we can point to indicating an effect of culling? This is of current concern, for Canada has approved a cull of Grey Seals to encourage the recovery of cod, and the Baltic States are considering a cull for the same reasons.

Fishermen want the cull, politicians are sympathetic, and marine scientists are unanimous in opposing culling. This is a familiar stand-off. What’s needed is evidence.

And now there is some, and it illustrates just how complicated ecosystem dynamics are.

Sable Island is an arc of sand on the Scotian Shelf, where Grey Seals breed in large numbers, in a region where cod were once abundant (oceantrack’org)

It involves cod. Following the moratorium on fishing North Atlantic Cod following the collapse of stocks in the early 1990s, everyone assumed the stocks would recover. They didn’t. But Grey Seal numbers exploded to around 400,000, particularly those breeding on Sable Island on the Scotian Shelf, near one of the past major cod stocks. That seems to indicate that seals have suppressed cod recovery, and therefore culling ought to help.

475 ships have wrecked on Sable Island since the 17th Century. Feral horses are the only permanent residents (getimage.php)

Instead the story goes like this. When the Scotian Shelf populations of cod and haddock, both large bottom predators, crashed from overfishing in the early 90s, the result was a major restructuring of the food web, a ‘regime change’ of the sort we have now learned to expect to occur. With the loss of the cod and haddock, planktivorous fish like herring, capelin and sand lance, as well as macro-invertebrates like Northern Shrimp and Snow Crabs became abundant instead – hugely so in some cases, and they have supported alternative fisheries. A new and stable balance of species seemed to have developed, with cod and haddock unrecovered. Grey Seals numbers increased greatly during this time.

Herring exploded in numbers, but have now crashed (fisherycrisis.com)

But this was not in fact a stable system. The biomass of fish in the system increased to an estimated 10 million tons, where carrying capacity is estimated to be less than half of that amount. The fish ran out of food – the zooplankton abundance crashed, the herring and capelin starved, and their populations crashed.

And then, with the herring and capelin gone as predators on cod and haddock larvae, cod and haddock have begun to recover. Particularly haddock. A return to the earlier food web appears to be underway, though how far it gets is unknown, for of course so much else is also involved, such as the impact of climate change, pollution, and continued fishing.

Cod show signs of some recovery (fisherycrisis.com)

Haddock recovery is greater (fisherycrisis.com)

The really good news is that ‘regime changes’ can reverse back to what previously existed. And in this case, in this ecosystem, the evidence indicates that Grey Seals, though obviously eating fish, are not responsible for preventing the recovery of the cod over the past two decades.

Since culling seals probably has no impact on the recovery of overfished populations, decisions to cull them anyway are then political, disregard science, and are so unfortunate.

Grey Seals, Sable Island, waiting to be culled (theglobeandmail.com)

Tags: cod recovery, culling seals, Grey Seals, Sable Island
Posted in Marine Conservation, Sustainable fisheries | Comments Off

Fishing the Arctic

Sunday, March 31st, 2013

The Arctic Ocean ought to be pristine and well protected from overfishing. Too much ice cover until very recently and the wisdom derived from decades of bad experience elsewhere ought to keep the ocean, both in the coastal EEZs and in the huge international waters in its center, safe from the disasters of overfishing that have occurred everywhere else. We are certainly smart enough to learn by our mistakes.

Lawren Harris painted Baffin Island around 1931. This is a summer impression of the north end of the island, the fifth largest in the world (artcountrycanada.com)

The question is not whether there should be any fishing at all – such environmental idealism now has little influence in our real world – but that the fishing needs to be sustainable. Vast potential fisheries will open up as the Arctic ice thins and recedes with the warming climate, but how will the usual overfishing be prevented?

The Inuvialuit of Canada’s Western Arctic have dealt with this question by getting the Federal Government in Ottawa to declare the Beaufort Sea off limits to commercial fisheries, at least for now. Meanwhile more than 2000 scientists, mostly from the Arctic coastal countries, have signed an open letter calling for zero commercial fishing until the changing ecology of the sea is understood.

Is some optimism therefore justified? The pressures of commercial fishing suggest it isn’t.

Russian trawlers at Murmansk, the main Russian port on the Barents Sea (barentsobserver.com).

To start with, Arctic fish populations have not been in any pristine condition for quite a long time, for catch data from 1950 to 2008 were radically under-reported. About 75 times more fish were caught than the various nations reported – a remarkable total of around 950,000 tons. The main offender was the Soviet Union/Russia, reporting a commercial catch of 12,700 tons instead of the 770,000 tons actually caught. The US and Canada acknowledged subsistence fishing by their coastal native communities, but each reported catches of zero instead of a more accurate 90,000 tons.

And of course the pressure to fish continues to build. Canada’s first Arctic commercial fishery has recently developed in the coastal waters around Baffin Island – in the jurisdiction of Nunavut. The fishery is for northern populations of Greenland Halibut, also known as turbot.

Greenland Halibut, or turbot, is a bottom dwelling cold water species that will shift further north as sea temperatures warm (sirena.dk)

Greenland Halibut grow slowly but live long in cold water (marlin.ac.uk)

The Nunavut communities need jobs, and the fish appear to be plentiful. More vessels, both inshore gill-netters and deeper-water trawlers, are entering the fishery. Quotas are rising and the fishery is expanding. There are calls for a deep-water port in northern Baffin Island for the trawlers to off-load so they don’t have to go to southern Greenland to do so. It all looks like a success story.

But it isn’t. In fact it has all the features of the boom phase of a boom-and-bust fishery, the sort we have endured over and over again around the world over the past century. It is all too familiar and will, as always, be difficult to resolve.

For instance, we don’t know at what age or size the fish become sexually mature, and we don’t know how fast – or slowly – they grow, or how long they live. How can we manage the fishery in such ignorance? We can’t.

Gill-netters are more selective than trawlers, and catch larger (and many fewer fish (from Anna Olafsdottir’s Powerpoint at scibd.com)

Trawlers catch 3-4 million fish and 5-6 thousand tons of them annually, much more than do the gill-netters (from Anna Olafsdottir’s Powerpoint (scribd.com)

The conflict between gill-netters and trawlers is heating up, with the gill-netters upset by the growing intrusion of the trawlers. And they should be. Fewer than 15% of caught fish should be less than 45cm long – the major regulation in place to try to protect the fishery – and most trawlers far exceed this. Because trawlers take smaller fish than the more selective gill-netters, they catch many more fish to meet their quota.

Regulation of the fishery is a responsibility of the DFO of Fisheries and Oceans Canada. This is not an incompetent organization, but the ruling Harper government has so reduced the funding of DFO that no-one is available anymore to do the work. As a result, existing regulations are not enforced, and new ones are not developed.

Collateral damage: Greenland Sharks are the most northern of sharks, grow to about 6 meters long, are considered ‘near threatened’ on IUCN’s Red List – and are worrisome bycatch of the Greenland Halibut fishery (biologybiozine.com)

Solutions exist – support the gill-netters, restrict the trawlers, gather fisheries data, limit the expansion of the fishing fleet, support the coastal communities, and at least remember the precautionary principle. None of this is impossible, but will take community leadership and involvement.

So what do we have? A number of nations are about to compete aggressively for opening resources in the Arctic Ocean; the marine ecosystem is changing in ways we don’t yet understand; coastal fisheries are expanding yet lack meaningful regulations; coastal communities face uncertain futures and are in need of access to commercial fishing; international agreements on how to deal with any such problems don’t exist; and the unreported fishing of the recent past has had an unknown impact on current fish populations.

What we have at the moment is familiar chaos. We know that the Arctic is not a productive, resilient marine ecosystem, but we are treating it as if it is.

Certainly we are capable of learning from our many past mistakes. It still is not too late to ensure our Arctic exploitation is sustainable, and not just business-as-usual.

We can do better this time.

Tags: Arctic commercial fishing, Arctic fisheries, Greenland Halibut fishery, sustainable fishing in the Arctic, unreported Arctic fishing
Posted in Arctic Issues, Sustainable fisheries | Comments Off

Losing Apex Predators

Monday, February 11th, 2013

We’re losing or have already lost the apex predators from most of our ecosystems. This has been going on for a long time – remember saber toothed tigers? – so it’s obviously not news that we are a particularly difficult species to co-exist with.

Over the past few decades global capture fisheries have added most of the large fish species of any commercial value to the list of missing apex predators. Among those that are still with us, an unexpected response has occurred.

In a comparison of 37 commercially fished stocks, the majority matured earlier and at a smaller size. The effect is clearest in heavily fished populations.

The size of first spawners of Arctic cod has declined, as it has in many other heavily fished species (nature.org).

Is this a genetic change, an evolutionary shift towards smaller size-at-age due to the selective harvesting of the oldest, largest and fast-growing individuals? If it is, it is a dramatic change, and will be difficult to reverse.

It could as well be a response to climate change, with physiological declines in growth rates occurring due to increasing sea temperatures and decreasing oxygen in warmer oceans.

At the same time, we wonder why fish that we have overfished don’t recover when we stop harvesting them. With their huge reproductive potential, fish surely should be resilient, and recover quickly. Famously, though, the cod of the northwest Atlantic have not recovered from their collapse.

The famous graph of exploitation of cod in the northwest Atlantic, leading up the moratorium in Canada in 1992. (Wikipedia.org)

Why not? What stops or delays recovery? And what have we actually learned about the impact of the damage we have done to marine ecosystems?

In fact we have learned quite a lot. We have learned that the responses of an ecosystem to the loss of apex predators are likely to be complex and convoluted, and often unpredictable. Shifts occur within the community of species, involving changes in mortality rates, growth rates, competitive interactions, and prey-predator relationships. (Two fine reviews worth reading were published in Science: Estes et al, July 15, 2011; and Garcia et al, March 2, 2012)

Pandalus borealis, the northern shrimp, became abundant after the collapse of cod, and is in part responsible for the lack of cod recovery. It is also the sweetest shrimp you would ever want to eat. (biology.com)

We have also learned that sufficiently perturbed ecosystems break abruptly into alternative stable states that are usually of lower trophic status and of far less commercial value. Coral reefs have become algal covered rubble. Jellyfish have replaced fish as top consumers.

We have learned that trophic degradation is an inevitable outcome of eliminating or radically reducing apex predators.

And we have learned that there are limits to resilience.

Iconic cod are showing signs of recovery in the northwest Atlantic – not enough to lift the moratorium, but enough to suggest hope lives (ctv.news0

Out of these fisheries disasters has comes some decent advice. For instance, fishing pressure should be spread over more species and sizes, probably netting more fish, but reducing the risk of wiping out a species or restructuring the community. Biomass drops but not biodiversity,
a more ecosystem-based approach.

But also we are aware that the only truly reasonable response is to try to restore the apex predators. If we don’t, biodiversity will decline, trophic degradation will continue, ecosystem phase shifts will occur, and the current global mass extinction will just continue. The world becomes ever more diminished.

Cod captured by trawler in 1949 were often huge. Nevermore. (heritage.nf.ca)

Does it help to understand the reasons for a catastrophe, if there seems to be little chance of preventing or recovering from it?

The answer must be yes. If recovery from the catastrophe is even remotely possible, we can encourage it. And we can use our knowledge to mitigate the impact of other catastrophes-in-waiting.

Tags: apex predators, cod recovery, fish resilence, fisheries collapse, trophic degradation
Posted in Marine Conservation, Sustainable fisheries | Comments Off

Measuring Ocean Health

Tuesday, October 16th, 2012

On a scale of one to 100, the health of the oceans has been given a 60.

We now have an index of ocean health for coastal waters – both global and national. Published in Nature in August, and the result of a huge amount of analysis by a large number of people, it has received a lot of generally favorable press attention. It is intended to be a measure of sustainability, representing benefits that a healthy ocean can provide to people.

The global index of 60 is the area-weighted average score of 10 goals. A comparable graph has been constructed for each of the 171 countries and associated territories that have any coastline at all (oceanhealthindex.org).

The website associated with the Index is excellent. It lets you explore the scores of each country goal by goal, with some detail on what the scores mean actually mean. It’s worth a visit just to see the graphics. If you want to see all the goals for all the countries on a single table, then you’ll need to go to the supplementary material published with the Nature article.

The index for countries ranges from 36 (Sierra Leone) to 73 (Germany and the Seychelles). For the US it is 63, for Canada 70.

The Seychelles, with the highest index (driversforce.ca)

At first blush, this all seems to make some sort of intuitive sense.

But what does it really mean? Unless we have confidence in the choice of goals and the methods of measuring them, the value of the Index may be very limited.

There are some goals (Natural Products, Carbon Storage and Coastal Protection, for example) that look particularly useful – they are based on reliable data and not too many assumptions, and result in a decent spread in scores.

But in contrast, there are two examples (the Mariculture half of the Food Provision goal, and Tourism) where 90% of the world get scores far too close to zero, while a very few countries get around 100. Both goals are important to include, but they clearly need better ways to measure them. Including them at this stage undermines the validity of the Index.

The scores for Fisheries (the other part of the Food Provision goal) are worrisome for a different reason, for they can be difficult to interpret. Generally the scores are all quite low, which seems reasonable. But here a low score can mean either that overfishing has been extensive, or instead that fish are not being harvested up to sustainable limits.

Both the authors and the reviewers agree that this is a first cut that will be improved as more data are gathered. However, if the scores for a few of the goals are unreliable or ambiguous, then the Index is unreliable. And certainly reducing it all to a single number for the world, or even per country, becomes increasingly meaningless.

But I think there is a greater problem with the Index, one that is fixable.

How can we try to compare Barbados with Japan, or the Seychelles with Germany? We can’t, and we shouldn’t. Yet, if you look at the global distribution of index scores, some obvious patterns pop out. For instance, the countries with the lowest index scores are clustered along west Africa. (Map from oceanhealthindex.org)

If you then look at a global map of the 64 Large Marine Ecosystems that have been identified, covering all of the world’s coasts, those countries all share a single Large marine Ecosystem: the Guinea Current, LME #28. That does make sense – it ties the countries and their coastal problems together in a meaningful way.

The Large Marine Ecosystem: The Guinea Current (lme.noaa.gov)

So why not use the index to assess and compare LME’s instead of countries? We would then, for instance, be able to compare the Caribbean LME with the Mediterranean or any other LME, and not have to break it into many small island pieces, or alternatively have to compare it with the entire coastline of Canada or Russia. Comparisons become far more defensible.

This would encourage countries that share an LME to work together to make it more sustainable. In fact, most have agreed for years that the LME approach is the best way to go. The Index could and should provide strong evidence to support this.

So let’s get this right. The Index has great potential, but not in its current form. Its value is in its details, and in its use in guiding us on how to improve the health of LMEs, not in ranking and scoring individual countries.

The current global score of 60 tells us nothing.

Tags: limitations of ocean health index, lme #28, Ocean Health Index, ocean health index and large marine ecosystems
Posted in International Affairs, Marine Conservation, Sustainable fisheries, Uncategorized | Comments Off

Lobster Glut

Wednesday, September 26th, 2012

The Gulf of Maine, kept relatively cold by the Labrador Current and the tides of the Bay of Fundy, is largely enclosed by the fishing banks (gulfofmaine-census.org)

There have been too many lobsters on the coast of Maine this year.

Lobstermen set their many thousands of traps, and far too easily caught far too many. They had to sell them for about $2 per lb, and for many that barely paid for their fuel. Some quit for the season, feeling they couldn’t make any money. Others have just sold their catch for whatever they could get.

Lobster traps piled high on the dock of a lobster co-op in Friendship, Maine (photo Deborah Berrill)

In a world where most fish populations have been overfished, the lobster fisheries on the coast of Maine is a true anomaly, more now than it has ever been.

Why are lobsters so abundant, when other fisheries are in such bad shape?

One reason is historical. Long ago, Maine lobstermen established unusual conservation rules – undersized and oversized individuals can’t be kept when caught, and a female caught with eggs has her tail notched and becomes protected forever as a breeding female. But these regulations are nothing new. They may help, but they aren’t the cause.

Large lobsters (this one weighed 27 pounds) in the Gulf of Maine have no predators, not even human, and can live for many decades, breeding every couple of years (wazzup2day.com)

Another reason is the loss of predatory groundfish - few bottom feeding fish are left to prey on small and still vulnerable juveniles. Again, this is nothing new.

There’s more. In the past decade, sea urchins have been so overfished (the Japanese savor their gonads) that it’s hard to find any now. They show little sign of recovery. As a result kelp beds have flourished in the absence of sea urchin grazing, providing lobsters with unlimited cover. But this has also happened before.

The lobsters are also very well fed, for the lobstermen of the gulf bait their traps with herring, and lobsters feed well in the traps until they molt to a size large enough to be harvested.

And then of course the Gulf of Maine has warmed by a couple of degrees centigrade over the past decade, modifying lobster growth rates, molting cycles, and wandering behavior.

Sea surface temperatures in the Gulf of Maine have been gradually rising. The warmest on record ever occurred in the summer of 2012 (neisa.unh.edu)

Do all these add up to enough to account for the current glut of lobsters? We don’t know.

A couple of weeks ago, in letters to the governors of New England coastal states, the US Secretary of Commerce wrote:
“I have determined that a fisheries failure due to a fishery resource disaster will exist for the Northeast Multispecies Groundfish Fishery ..it seems unlikely that all economic impacts of the proposed catch limits for 2013 can be mitigated solely through fisheries management measures. While the precise cause of stock declines is unclear,’undetermined causes’ is an allowable cause for disaster relief.”

Undetermined causes. We speculate about the causes, but we actually don’t know why the groundfish have not recovered. We don’t why the sea urchins have not recovered. We don’t know why lobsters have become to abundant.

The Gulf of Maine is not unique. It’s just a well documented example of what is happening globally.

Uncertainty, ever-present in our understanding of ecosystems, grows ever greater. We are on a new trajectory, into a world of increasing uncertainty that we we can try to monitor but that we cannot predict.

Tags: groundfish decline, Gulf of Maine, lobster glut, uncertainty, warming Gulf of Maine
Posted in Marine Conservation, Sustainable fisheries | Comments Off

Moaning the Blues

Thursday, July 12th, 2012

Blue Whales are in the news just now, with a few feeding off the coast of California and around Sri Lanka where enthused whale watchers can see them. An adult that weighs 200 tons and is 30 meters long, twice the size of the largest dinosaur, is an extraordinary sight, and a rare one.

A Blue whale breaches backwards, exposing the rorqual or expandable folds of its huge throat. This is an iconic picture, a view seen by very few. (binbrain.com)

They were hunted almost to extinction in the 20th Century. In the Southern Ocean, 200-300 thousand of them once fed on the huge schools of krill feeding along the Antarctic ice edge. By the time the International Whaling Commission agreed 1n 1973 on a moratorium on hunting the Great Whales, perhaps 700 were left in the Southern Ocean. That’s very close to the edge.

Though the Southern Ocean population was by far the largest, smaller populations roamed elsewhere. In fact, three subspecies probably exist, varying a little in size at maturity and maximum size, isolated from each other in different oceans. One lives in the North Atlantic and the North Pacific, with 1-2,000 whales in each region, genetically connected by migrants through the Arctic ocean. Another population of about 2000 is the remnant of the slaughter of the last century in the Southern Ocean. The third, known as Pygmy Blue Whales because they only grow to about 24 meters long instead of 30, lives in the Indian Ocean, with somewhere between 2 and 10 thousand individuals.

Close view of the blow hole and bow wave of a Blue Whale (nmfs.noaa)

So some recovery has occurred – about 7% increase overall per year. That sounds pretty good, but remember where they started. The population in the Southern Ocean is currently about 1% of its size before the whalers hunted them, and is still considered ‘Endangered’.

So what lies ahead for the Blue Whales? They turn up where krill become most abundant, even if only temporarily – this is what has brought some this year to the coast of California. An adult Blue needs a lot of food, and may eat about 4 tons of krill (40 million krill!) per day.

Krill are euphausid shrimp that eat phytoplankton, grow to 5-10cm, and prefer cold, upwelling water (sciencepoles.org)

But we are also fishing for more krill in the Antarctic now. As well, as climate change continues to warm parts of the Antarctic, particularly around the West Antarctic Peninsula, krill competitors like salps are doing well. They are too low in food value to nourish whales, or humans for that matter.

A ball or swarm of krill – but imagine one that is several km or miles wide: in ideal conditions along the edge of the Antarctic ice sheet, they once got that big (anniekatek.blogspot.com)

An adult female Blue whale should reproduce every 2-3 years when she is well fed. When she is not, she is unlikely to reproduce at all. When krill supplies are diminished, further population growth of the Blue whales will be very limited.

A female Blue whale with its calf. A calf is 7 meters long at birth, weighs 2700 kg, drinks 400 liters of milk per day, and gains 90 kg per day. (expeditions.com)

Blue whales call when they are not actively feeding. The calls sound like very low, down-sweeping moans, and males probably do all the moaning, trying to attract females, and perhaps warn other males of their presence. We don’t know much about this.

A moan typically lasts about 30 seconds, at a very low frequency of 10-40 Hz. That is really low – we can’t hear anything below 20 Hz, and 40 Hz is still a rumbling base we find barely audible. Such low frequencies travel far in the ocean, but at the same time they can get lost in the background of the noises our ships produce.

Living in such relatively small and dispersed populations, calling to each other in a noisy sea, Blue Whales have a huge challenge of finding one another.

Still, it is tantalizing to think we might again share the oceans with this amazing beast. We are generally attracted to things that are very big and we tolerate other animals that don’t compete directly with us.

Blue Whale of the north Pacific population.

But there isn’t a whole lot left in the sea for us to eat. A large and hungry competitor for that food we want to have instead has is playing a hand it cannot win.

The Age of the Great Whales ended when they were hunted out of all the oceans. Remnant populations may continue to exist. But the Age of Great Whales will not return. We can’t afford it.

Tags: blue whale recovery, blue whale slaughter, blue whales and krill, blue whles, krill
Posted in Marine Conservation, Sustainable fisheries | Comments Off

The Open Arctic

Thursday, June 14th, 2012

Everyone is preparing for an Arctic Ocean open for business at least through the summer months.

Seasonal shipping is increasing, and ports are growing, especially along the Russian coast.

The North Pole, April 2004: HMS Tireless, a nuclear sub, measured sea ice thickness of the melting ice cap (seaice.org.uk)

The Arctic rim countries – Canada, Norway, Denmark, Russia and the US – are under some pressure to agree to a moratorium on exploiting the Arctic fisheries at least until enough is known about the ecosystem to do so sustainably.

Beluga whales feed on a school of Arctic cod (the dark streak), a species of potential commercial value but about which we know very little (arkive.org)

The tension over who if anyone owns any of the international waters in the huge center of the Arctic continue to grow, with Russia planning to reopen long closed Soviet bases, Canada considering using drones to monitor the region, and the US getting increasingly nervous about not having a vote in the UN negotiations concerning international boundaries.

The international water of the Arctic Ocean (red lin e)(oceansnorth.org)

Meanwhile China and South Korea are building icebreakers and intend to be players in the search for Arctic fish and other resources.

And then there are the oil companies.

The huge BP Deepwater Horizon spill in the Gulf of Mexico in April 2010 is largely forgotten. Canada, the US and Norway are all inviting oil companies to bid for licenses to explore for oil and natural gas along their Arctic coastlines from Alaska and the Beaufort Sea to the Barents Sea. After a relentless, seven year campaign, Shell begins to drill on the Alaskan North Slope this summer, with Greenpeace watching closely. All the companies are eager to drill in international waters when that becomes possible.

Canada opens the Beaufort Sea for bids for drilling licenses

They are preparing to work in the cold, in darkness, in sea ice a long way from any supportive infrastructure. Still they claim development can be done sustainably.

In fact, nine of the major oil companies, including Statoil, Total, ExxonMobil, ConocoPhillips, and Shell, have launched a research program where they will assess how spills flow in the Arctic, how to track them remotely, and how to recovery spilled oil. They will do this with ‘controlled’ spills.

Missing from this initiative are the Russian companies, Gazprom and Rosneft. No one seems confident that they will comply with regulations that the others accept. The Gazprom rig that capsized off Sakhalin last December, killing 50, is not reassuring.

Actually, no company is ready for offshore drilling in the Arctic Ocean, for no proven method for clean-up there exists.

Resistance to drilling has failed. The US sees the Arctic resources as part of its route to energy independence. Norway needs to replace its lucrative but depleted offshore southern oil fields with new northern ones. Canada wants to sell its resources to anyone who will buy them. Russia is Russia.

We hoped the rules of the game might be different in the Arctic as it opens up, based on all that we have learned over the past few decades. In fact they look exactly like they always have: power wins; the idea of endless economic growth remains unchallenged; resources exist to be exploited; environmental concerns are recognized and then largely ignored.

As elsewhere in our modern world, our response has become not to stop it, but at best to try to make it less bad.

At the least, a vigilant and activist press is increasingly critical – reminding us of past initiatives and failures, of the importance of evidence and precaution, and of the fragility and vulnerability of our natural world.

Walruses meet to debate the future of the Arctic Ocean (washingtonpost.com)

Tags: Arctic development, Arctic fisheries, Arctic oil exploration, Arctic shipping
Posted in Arctic Issues, Energy sources, Global warming, International Affairs, Sustainable fisheries | Comments Off

Fishing for the Halibut

Thursday, April 26th, 2012

The Atlantic Halibut is an extraordinary fish, once one of the world’s largest. Old reports suggest males could have grown to 700 pounds and 15 feet (320 kg and 4.7 m). Long lived, slow growing, late maturing, and easily caught by bottom trawls and long lines, they were quickly overfished once people acquired a taste for them. Now not many are left, and the species is labelled Vulnerable or Endangered, depending on the agency assessing them.

Halibut are bottom dwelling flatfish that prey on other fish as well as crustaceans. This is the Pacific halibut, which has been fished sustainably. Atlantic halibut are too rare to be able to photograph in the wild like this (marinesciencetoday.com)

Fishing along the New England coast and on the offshore fishing banks remains a disaster. Collapsed stocks like halibut recover very slowly, if at all, and even cod, which ought to be more resilient, have failed to show signs of recovery. Quotas are small and getting smaller, and so are fishing fleets.

An 8 foot, 444 pound Atlantic halibut caught off Norway in 2008, no doubt one of the last of this size (tiptheplanet.com)

Whole Foods Market is going to sell only the fish species considered sustainable by the Monterrey Bay Aquarium and the Blue Ocean Institute, and that eliminates the Atlantic halibut – as it should. Plenty of other markets exist, but it sets a good example. We simply should not be eating any wild caught Atlantic halibut.

A very new method of aquaculture involves submerged, ‘deepwater’ AquaPod Net Pens – geodesic spherical enclosures that have been used for cod, salmon, and other species, but not yet for halibut.

Now there is a proposal to farm Atlantic halibut in a bay on the central coast of Maine, starting with one Aquapod about 30 ft in diameter, tethered to the bottom by an 18,000 pound anchor, able to spin out with tide in a 150 ft radius.

An AquaPod Net Pen is lifted by crane onto a barge and then later into deeper water offshore (oceanfarmtech.net)

The halibut would be raised in a hatchery from egg to settled stage, and then moved to the AquaPod, fed fish pellets designed for halibut, monitored to prevent over-feeding, and grown rapidly to marketable size.

An AquaPod is neutrally buoyant, can be rotated to clean, and can be partly emerged or totally submerged depending on ocean conditions (ecofriend.com)

But will it work? There are legitimate environmental concerns about the impact of uneaten food and feces on the existing bottom community, and very careful monitoring is essential. Though the Aquapod would be set in the deeper water where the dozen or more lobstermen who work the bay don’t set many of their thousands of lobster pots, other commercial fishing would be blocked.

Each year farmed fish make up more of the total fish production

Some halibut farming will be helpful. Done right, done carefully, it should work. But AquaPod culture of halibut is very much an experiment, and it needs to occur where other fishermen are not affected, and where coastal communities are sparse. A bay that is saturated with lobsterpots, cottages, summer residents and their boats is not the place for this experiment.

Soon more half of the world’s marketed fish will be farmed – a reflection not just of the collapse of wild caught fisheries but also of the growth of farming.

So let’s farm halibut. Let’s try to farm them in AquaPods. But let’s do it carefully, in places where other users are least affected, and where experimental failure has the least impact.

Tags: Aquapod Net Pens., Atlantic halibut, fish farming, halibut aquaculture
Posted in Eat it or not, Marine Conservation, Sustainable fisheries | Comments Off

The Acidification of Oysters

Monday, April 23rd, 2012

Maybe you read about this recently. It seems to me to be quite amazing.

A die-off of oyster larvae at the Whiskey Creek Shellfish Hatchery on the Oregon coast has been correlated with – and almost certainly caused by – a small increase in the acidity of the sea water the larvae were exposed to in their first 24 hrs.

Oyster larvae need critical levels of CaCO3 for their shells to develop, and these levels drop as CO2 levels in the water increase.

Oyster larvae (marineticsinc.com)

The report was published in April in the journal Limnology and Oceanography by three scientists (Richard Feely, Alan Barton and Burke Hales). Then Jeff Barnard, Environmental Writer for the Associated Press, published a summary of the study, and pretty well everyone took notice. When I Googled ‘oyster larvae dying’, most of the first 300 hits were copies of his article republished by American and global news websites.

Oyster life cycle (scienceinthetriangle.org)

All the reports, not just AP’s, emphasize that this is some of the first solid evidence of the potential impact of ocean acidification on a valuable fishery, though in fact oyster growers have been concerned about the threat of acidification for some years.

Anything that has a calcareous skeleton is sensitive to increased acidity (noaa.gov)

The event is worrisome, of course, for ocean acidification will continue for many decades, even once (or if?) we stop the increase in atmospheric CO2. Now we know that a very small change in ocean acidity can have a large impact on a sensitive species.

As atmospheric levels of CO2 increase, so do levels in the ocean, resulting in increasing ocean acidity (e360.yale.edu)

But what’s unexpected is the attention the journal publication and its AP description have received. It should signal to our political leaders in North America that in fact people really are worried about the accelerating effects of global warming.

How much evidence is needed? The death of some oyster larvae won’t change the beliefs of most of the US Congress, but it ought to.

It also won’t effect the politics and business of oil that dominates the Canadian economy, but it should.

They say we get the leaders that we deserve, but we don’t deserve this.

The die-off of the oyster larvae cannot be shrugged off as irrelevant or insignificant.

So we are warned.
Again.

Tags: ocean acidification, oyster die-off, oyster larvae
Posted in Global warming, Sustainable fisheries | Comments Off

Eating Jellyfish