Tag: ecosystem collapse

Author SuzannePosted on Categories Sonoma Coast, WildlifeTags , , ,

Four Bay Area residents arrested on suspicion of abalone poaching, black market sales 

Mary Callahan, THE PRESS DEMOCRAT
Four suspected poachers believed to have removed hundreds of red abalone illegally from the beleaguered North Coast fishery were arrested this week at their Bay Area homes at the conclusion of a five-month investigation, according to the California Department of Fish and Wildlife.
The suspects are part of a larger crew used to collect abalone offshore of Sonoma and Mendocino counties for black market sales to a network of individuals, officials said. It does not appear the shellfish were sold to markets or restaurants.
The suspects — Thepbangon Nonnarath of Oakley, Dennis Nonnarath of El Sobrante and Thu Thi Tran and Cuong Huu Tran, both of San Jose — were arrested on a variety of charges that included conspiracy to commit a crime, as well as illegal commercial sales, falsification of abalone tags and exceeding the season limit of abalone.
Their arrests come as fishery regulators are grappling with a rapid decline in red abalone populations, thanks to shifting ocean conditions that have prompted significant starvation of the prized mollusks, due in part to exploding purple urchin populations that have grazed much of the ocean floor clean.
Read more at: Four Bay Area residents arrested on suspicion of abalone poaching, black market sales | The Press Democrat –

Author SuzannePosted on Categories Habitats, Sonoma Coast, WildlifeTags , , , ,

Unprecedented delay in California abalone season

Mary Callahan, THE PRESS DEMOCRAT

Wildlife managers hope lessening pressure on the imperiled mollusks will help the fishery rebound from a catastrophic mix of ocean conditions that have prompted extensive starvation in abalone stocks.

In a normal year, veteran diver Matt Mattison would likely have started this weekend clad in neoprene, plying the waves off the Sonoma Coast, eager to bag his first red abalone of the season.
Instead, the Monte Rio resident was among a group of volunteers who fanned out Saturday along the North Coast’s most popular abalone hunting grounds to head off any divers or rock pickers who mistakenly turned up and to inform them the traditional season start has been delayed.
A jubilant occasion that typically draws hundreds, perhaps thousands, of restless abalone hunters to coastal waters each year, the April 1 opener is a little like Christmas for those who pursue the succulent sea snails. It’s a rite of spring.
But after four decades of time-honored ritual — cause for reunions of family and friends on the Sonoma and Mendocino coast every year — the California Fish and Game Commission has taken emergency action curtailing this year’s season, axing both April and November from the calendar and sharply reducing the allowable annual catch, from 18 abalones to 12.
It will be the first April since 1921 — a time when the season began in mid-March — that red abalone cannot legally be harvested, according to Jerry Kashiwada, an environmental scientist with the state Department of Fish and Wildlife.
Read more at: Unprecedented delay in California abalone season shuts down North Coast in April | The Press Democrat

Author SuzannePosted on Categories Climate Change & Energy, Sonoma Coast, WildlifeTags , , , ,

Ocean rhythms are changing, ocean wildlife dying

Mary Callahan, THE PRESS DEMOCRAT

Mass-starvation events have hit a spectrum of other West Coast marine wildlife, mostly due to the collapse of food chains brought on by warmer ocean water.

In any other year, the large bins of Dungeness crab that are loaded dockside in this busy fishing village and rolled out by truck to be sold and served during the holidays would seem like no big deal.
But after an unprecedented delay in the 2015-16 commercial season forced local crabbers to leave their boats tied up through winter and on into spring, the tons of meaty crustaceans landed in port this month have been a welcome sign of normalcy restored, if only for a moment.
For here on the edge of the Pacific, where commercial fishing remains a way of life, once reliable ocean rhythms have been seriously unsettled of late, confounding those who depend on predictable, seasonal cycles and highlighting future uncertainties.
Even the current Dungeness season lurched off to a bumpy start, with the fishery opening piecemeal and mostly behind schedule, a symptom of widespread marine anomalies that have prevailed for the past three years, threatening everything from seabirds and sea lions to treasured catches such as salmon and abalone.
“The ocean is changing,” one glum crabber aboard the vessel New Horizon said while waiting to unload his catch recently at Tides Wharf. Offshore a strong storm was building and the fisherman summed up the fishing industry’s environmental troubles with hard-earned experience.
“Irregularity “is starting to look like the new normal,” he said.
Scientists and fishermen alike are unsure about the degree to which recent upheaval fits within the ocean’s normal rhythms — which are complex — or is part of some longer-term trend, perhaps linked to global climate change and its many ripple effects.
It’s likely a bit of both, given the context of the Earth’s warming, though more immediate atmospheric conditions have been the primary suspect, scientists say.
“Climate change syndrome is definitely having an impact,” said John Largier, professor of coastal oceanography at the UC Davis Bodega Marine Laboratory. “…What is very difficult to tell is how much.”
It appears that an expanse of high-temperature water along the coast of North American known as “the Warm Blob” is mostly to blame for recent disturbances affecting the coast of California, causing significant redistribution of wildlife, disruptions in the food web and large-scale mortality in a variety of animals.
Read more at: Year in Review: Ocean changes upend North Coast fisheries | The Press Democrat

Author SuzannePosted on Categories Climate Change & Energy, Sonoma Coast, WildlifeTags , , ,

Global marine analysis suggests food chain collapse in oceans

A world-first global analysis of marine responses to climbing human carbon dioxide emissions has painted a grim picture of future fisheries and ocean ecosystems.
University of Adelaide, Australia

Published October 12 in the journal Proceedings of the National Academy of Sciences (PNAS), marine ecologists from the University of Adelaide say the expected ocean acidification and warming is likely to produce a reduction in diversity and numbers of various key species that underpin marine ecosystems around the world.
“This ‘simplification’ of our oceans will have profound consequences for our current way of life, particularly for coastal populations and those that rely on oceans for food and trade,” says Associate Professor Ivan Nagelkerken, Australian Research Council (ARC) Future Fellow with the University’s Environment Institute.
Associate Professor Nagelkerken and fellow University of Adelaide marine ecologist Professor Sean Connell have conducted a ‘meta-analysis’ of the data from 632 published experiments covering tropical to artic waters, and a range of ecosystems from coral reefs, through kelp forests to open oceans.
“We know relatively little about how climate change will affect the marine environment,” says Professor Connell. “Until now, there has been almost total reliance on qualitative reviews and perspectives of potential global change. Where quantitative assessments exist, they typically focus on single stressors, single ecosystems or single species.
“This analysis combines the results of all these experiments to study the combined effects of multiple stressors on whole communities, including species interactions and different measures of responses to climate change.”
The researchers found that there would be “limited scope” for acclimation to warmer waters and acidification. Very few species will escape the negative effects of increasing CO2, with an expected large reduction in species diversity and abundance across the globe. One exception will be microorganisms, which are expected to increase in number and diversity.
From a total food web point of view, primary production from the smallest plankton is expected to increase in the warmer waters but this often doesn’t translate into secondary production (the zooplankton and smaller fish) which shows decreased productivity under ocean acidification.
“With higher metabolic rates in the warmer water, and therefore a greater demand for food, there is a mismatch with less food available for carnivores ─ the bigger fish that fisheries industries are based around,” says Associate Professor Nagelkerken. “There will be a species collapse from the top of the food chain down.”
The analysis also showed that with warmer waters or increased acidification or both, there would be deleterious impacts on habitat-forming species for example coral, oysters and mussels. Any slight change in the health of habitats would have a broad impact on a wide range of species these reefs harbour.
Another finding was that acidification would lead to a decline in dimethylsulfide gas (DMS) production by ocean plankton which helps cloud formation and therefore in controlling Earth’s heat exchange.

Source: Global marine analysis suggests food chain collapse — ScienceDaily