Tag: kelp

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

Kelp forests surge back on parts of the North Coast, with a lesson about environmental stability

Alastair Bland, BAY NATURE

An unexpected darkness has recently fallen over the seafloor of the Northern California coast – the shadows cast by bull kelp.

The giant marine alga nearly vanished after a perfect storm of environmental and ecological events, including a marine heatwave and a population boom of seaweed-eating sea urchins, disrupted the marine ecosystem between 2013 and 2015. Kelp forests collapsed by more than 90 percent in Northern California, and with them went both scenic appeal and marine biodiversity. Red abalone, which graze on kelp, starved in droves, and fish departed for deeper waters. What was left, and which persists in much of the region, is a bleak underwater landscape dominated by purple urchins and not much else.

But this year the bull kelp forests of memory have surged back along parts of the Northern California coast. Areas that were completely devoid of kelp as recently as last winter are now marine jungles of tangled underwater stems and dense floating mats of fronds. James Ray, a California Department of Fish and Wildlife biologist and kelp researcher, says the comeback seemed to begin in 2020 “with a little bump in kelp cover.”

“Now we’re seeing a much bigger bump along much of the coast,” he says.

The rapid resurgence, possibly the result of strong springtime upwelling of cold water, has other experts both delighted and a bit mystified.

“The rebound of the forests in Sonoma and Mendocino counties has been surprising and profound considering how devastated they were just a few years ago,” says Franklin Moitoza, a graduate student at Humboldt State who, working with a team of collaborators, has closely tracked kelp forest health and recovery. He says he has seen pronounced kelp regrowth from Bodega Bay to Trinidad within the past year.

Read more at https://baynature.org/2021/09/13/kelp-forests-surge-back-on-the-north-coast-with-a-lesson-about-stable-environments/?utm_source=Bay+Nature&utm_campaign=947f98b27d-BN+Newsletter+09%2F16%2F2021&utm_medium=email&utm_term=0_092a5caaa2-947f98b27d-199023351&mc_cid=947f98b27d&mc_eid=94a0107f8c

Author SuzannePosted on Categories Climate Change & Energy, Habitats, Sonoma CoastTags , , , , , , , , ,

Scientists grappling with persistent and alarming collapse of North Coast’s bull kelp forests

Mary Callahan, THE PRESS DEMOCRAT

Five years after marine scientists first sounded the alarm about a sudden collapse of the bull kelp forest off the Northern California coast, the state of the ocean offers little prospect of recovery any time soon.

Where lush stands of leafy kelp once swayed amid the waves, providing cover to young finfish and forage for abalones and other creatures on the ocean floor, a stark new world has materialized — one dominated by millions of voracious purple sea urchins that have stripped the ocean floor down to rock in some places. Were a tender frond of new kelp to sprout, it wouldn’t stand a chance of surviving long.

The barrens left behind are a stark and alarming contrast to what is typically one of the most thriving marine environments — seasonal kelp forests that support a rich ecosystem with life stretching from the sea floor to the surface, and up the food chain, supporting recreational and commercial fisheries and home to some of the North Coast’s most iconic wildlife, including abalone and sea otters.

The kelp forests also are a key barometer for the wider health of the world’s oceans, and without some recovery, their future as biodiverse stores for marine life and people hangs in the balance.

Laura Rogers-Bennett, a veteran biologist who works out of the UC Davis-Bodega Marine Lab, likened the kelp forest to a great floating woodlands stretching hundreds of miles along the coast.

“To lose 95% of your forest in a year and a half, that’s a catastrophe, an ecological disaster, and it’s had so much socioeconomic impacts, as well,” she said.

Read more at: https://www.pressdemocrat.com/article/news/scientists-grappling-with-persistent-and-alarming-collapse-of-north-coasts/

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

Seafood's new normal: An ecosystem at risk

Tara Duggan, SAN FRANCISCO CHRONICLE
In the shallow waters off Elk, in Mendocino County, a crew from the California Department of Fish and Wildlife dived recently to survey the area’s urchin and abalone populations. Instead of slipping beneath a canopy of leafy bull kelp, which normally darkens the ocean floor like a forest, they found a barren landscape like something out of “The Lorax.”
A single large abalone scaled a bare kelp stalk, hunting a scrap to eat, while urchins clustered atop stark gray stone that is normally striped in colorful seaweed.
“When the urchins are starving and are desperate, they will leave the reef as bare rock,” said Cynthia Catton, an environmental scientist with Fish and Wildlife. Warm seawater has prevented the growth of kelp, the invertebrates’ main food source, so the urchins aren’t developing normally; the spiky shells of many are nearly empty. As a result, North Coast sea urchin divers have brought in only one-tenth of their normal haul this year.
The plight of urchins, abalones and the kelp forest is just one example of an extensive ongoing disruption of California’s coastal ecosystem — and the fisheries that depend on it — after several years of unusually warm ocean conditions and drought. Earlier this month, The Chronicle reported that scientists have discovered evidence in San Francisco Bay and its estuary of what is being called the planet’s sixth mass extinction, affecting species including chinook salmon and delta smelt.
Baby salmon are dying by the millions in drought-warmed rivers while en route to the ocean. Young oysters are being deformed or killed by ocean acidification. The Pacific sardine population has crashed, and both sardines and squid are migrating to unusual new places. And Dungeness crab was devastated last year by an unprecedented toxic algal bloom that delayed the opening of its season for four months.
Read more at: Seafood’s new normal: An ecosystem at risk

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

North Coast kelp beds ‘like a desert’ this year

Mary Callahan, THE PRESS DEMOCRAT

Abalone diver Richard Hayman already had been observing troubling shifts in underwater conditions off the North Coast when he found himself gazing around the ocean floor in Arena Cove with a new level of alarm.

“It’s like a desert out there,” he recalled, describing a barren underwater landscape stripped of vegetation by colonies of purple urchins that vastly outnumbered the mollusks he sought. It looked, he said, “like a fire went through.”

During 25 years of diving, Hayman had come to know the area offshore the Mendocino County town of Point Arena as a source of succulent abalones, abundant and plump with meat.

 In June, he came ashore with his limit of three, despite a substantial reduction in the number of shellfish he saw. But they were so withered that, once removed from their shells, the creatures weighed less than a third of what they normally would.

“They’re starving to death,” the Calistoga man said. “It’s obvious.”

Hayman, 52, was among a dozen veteran divers who recently shared their observations at the midway point to the 2016 red abalone season, which resumes Aug. 1 after a month-long break and runs through November.

What they revealed was near consensus that all is not as usual out there, off the edge of the land, beneath the waves.

Scientists had predicted as much just before the season’s April 1 start, describing an unprecedented collapse of the North Coast’s iconic bull kelp forest and the resulting gloomy outlook for the abalone fishery and the overall ecosystem.

Divers reporting in over the past few weeks — people like Napa diver Andy Treweek, 55 — witnessed as much in some areas, where they discovered a few undersized abalone living on near-barren ocean floor.

Read more at: North Coast kelp beds ‘like a desert’ this year

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

Collapse of kelp forest imperils North Coast ocean ecosystem

Mary Callahan, THE PRESS DEMOCRAT

How to help: State scientists are seeking help with data collection and other activities, as well as observational accounts, photos and videos related to the urchin barren. Shared images and information should, if possible, include the date, location and depth at which they were acquired. Contact Cynthia Catton at Cynthia.Catton@wildlife.ca.gov or 875-2072.

Large tracts of kelp forest that once blanketed the sea off the North Coast have vanished over the past two years, a startling transformation that scientists say stems from rapid ecological change and has potentially far-reaching impacts, including on several valuable fisheries.
The unprecedented collapse has been observed along hundreds of miles of coastline from San Francisco to Oregon. The region’s once-lush stands of bull kelp, a large brown alga that provides food and habitat for a host of wildlife species, have been devoured by small, voracious purple urchins. In the most-affected areas, denuded kelp stalks are almost all that remains of plant life.
Scientists have described the landscape left behind as an “urchin barren.” Other factors, including warmer water, also are to blame, they say.
“It’s no longer a kelp forest,” said Cynthia Catton, an environmental scientist with the California Department of Fish and Wildlife, stationed in Bodega Bay.Laura Rogers-Bennett, another Bodega Bay scientist, said it is as if whole terrestrial forests were disappearing, only in this case they are underwater and out of sight.
“A lot fewer people swim through the kelp forest,” she said. “But if they do right now, they‘re going to really see that there are huge changes that have taken place in the last year and a half or so.
”The discovery has taken shape as California scientists and policy makers are raising a broader alarm over the ebbing health of ocean waters, pointing to their increasing warmth, acidity and other conditions that have affected wildlife and the fishing industry.
Read more at: Collapse of kelp forest imperils North Coast ocean ecosystem | The Press Democrat