Showing posts with label Oceans. Show all posts
Showing posts with label Oceans. Show all posts

Tuesday, 30 June 2020

Rapidly warming oceans have left many northern marine mammals swimming in troubled waters. But perhaps none more so than that strange and mysterious "unicorn of the sea," the narwhal.

by Larry Powell


Narwhals are cetaceans, a family of marine mammals which includes whales and dolphins. Most are found in Canada's Baffin Bay and Davis Strait, in the high Arctic and Atlantic Arctic. Others live off Greenland, Norway and Russia. Many spend several months over winter, beneath the ice-pack, feeding on fish, squid and shrimp and their summers in more open water. It's believed they're capable of diving as deep as 15 hundred meters and holding their breath for an astonishing 25 minutes! 
Narwhals breach through an opening in the ice-pack.                     Photo credit - US Fish & Wildlife.
A pod "breaches" through an opening in the sea-ice. 
A US Fish & Wildlife Service photo. 
They can weigh up to two thousand kilograms and reach a length of about five meters. They're much larger than some dolphin species, but tiny compared to the mighty blue whale. Many migrate along the ice's edge some 17 hundred kilometres from Canada to Russia.

The males grow long, spiral tusks - actually overgrown teeth - that can protrude up to three metres from their head. While they’re predators, narwhals are also preyed upon. Killer whales (orcas) are believed to be taking them increasingly as warming waters lure the orcas further north.

But man likely remains their prime enemy.

Indigenous hunters of Greenland and Canadian high Arctic - the Inuit - have, for centuries, depended on them as an important food source. Canada officially recognizes the right of the Inuit to hunt them. But they must adhere to a quota system. It's based on findings from periodic, scientific aerial surveys mandated by both Canada and Greenland, designed to protect narwhal populations from over-harvesting.

Recent numbers are hard to find. But one official survey in 2010 concluded that Inuit hunters took almost a thousand narwhals off Canada and Greenland that year.

So, just how intimately are narwhals tied to their world of ice and snow? 

"Narwhals are uniquely adapted to the extreme conditions of an Arctic existence," the study states, "and their evolution and ecology intrinsically tied to the past and present sea ice dynamics of the region." Narwhals are known to have lived through extreme climatic changes for thousands of years. Yet they're also thought to be among the most vulnerable to those changes of any of the northern marine mammals.

The researchers hoped, by studying their past, they could gain an insight into their future. What they found was concerning. Before and after the onset of the last ice age (LGM), more than 26 thousand years ago, both the number of narwhals and their genetic diversity were perilously low. But they "responded positively" to both the warming and expansion of habitat which occurred after it ended some 19 thousand years ago. Their numbers increased, and so did other marine predators like belugas and bowhead whales.

However, the benefits such animals enjoyed in that post-glacial period, may be coming to an end. "Many polar marine predators are being negatively affected by global warming, which is decreasing the availability of habitat and prey," the study finds. "Although the range and effective population size of narwhals increased post-LGM, their future in a rapidly changing Arctic is uncertain. Narwhal distribution will be further affected in the near future, as the species also faces increased human encroachment, changes in prey availability, new competitors and increased predation rate by killer whales."

Areas which were once inaccessible to people, due to ice and snow cover, are now receding. This is allowing more activities such as fishing, oil exploration and drilling. And narwhals are known to be easily disturbed, and to flee from areas they like to frequent in summer, like fiords, bays and inlets.

So, are their numbers crashing? 

The researchers admit, there's a good deal of uncertainty when it comes to population trends. World population estimates have ranged from 50 thousand to 170 thousand. As those estimates have wavered, so has their status on the endangered species list of the International Union for Conservation of Nature - from "nearly threatened" to "of least concern."

A veteran biologist with Fisheries and Oceans Canada, Dr. Steven Ferguson, has extensive experience observing marine mammals in the north. While he doesn't give hard numbers, he tells PinP, "Both the Baffin Bay and Northern Hudson Bay populations appear to be relatively constant and do not appear to be depleted."

However, the good news seems to end there.

"Populations off the eastern shores of Greenland," he goes on, "seem to be experiencing a decline. And two stocks off West Greenland, appear to be lower in abundance relative to the past."

So, will these wondrous "unicorns of the sea" continue to ply their ways through the world's northern oceans just as they have for so long in the past? Or are their numbers destined to dwindle to a dangerous few, like so many other of Earth's wild things?

Wednesday, 22 January 2020

Toxic Tides

One of the biggest challenges facing the aquaculture industry everywhere, is Lepeophtheirus salmonis, the sea-louse. 


 Sea lice, Lepeophtheirus salmonis, on farmed
Atlantic salmon, New Brunswick, CA.
Photo by 7Barrym0re



It’s a parasite which attacks both farmed and wild salmon (r.), causing lesions and infections which stunt their growth. But the costs of de-lousing are high. And so are the losses suffered by the industry in the marketplace. Many lice can actually kill many fish.


To fight back, the fish-farmers dump pesticides into the waters (below). But, because they’re released directly into the environment, they not only kill the lice, but place beneficial, “non-target” organisms at risk, too. And several of these live in the open ocean, beyond the confines of the  farms.
This image shows how industry applies pesticides within their operations.


The latest (but not the only) cautionary tale about the wisdom of this practise, has just emerged from Norway

A team of researchers there exposed (in the lab), an important food source for the fish, to varying levels of hydrogen peroxide (H202).  It's the active ingredient in several such products.  The food source  was a zooplankten called Calanus spp. (r.)


Calanus spp. Illustration by the

It's abundant in coastal waters where many salmon farms are located and is a key component in the North Atlantic food web. It's important, not only to young farmed fish, but to wild herring and cod, as well. 

The lab results were convincing.


In just one hour, at only 10% of levels the farmers would apply, 92% of the juvenile Calanus spp. and all of the adult females died. And, at much lower doses (1% or less), the ability of the organisms to take in oxygen was greatly reduced. Their “escape response” was destroyed, making the likelihood of them being eaten by predators, "extremely high." 

The researchers concluded,  "Present recommended levels of application underestimate the impact of the pesticide on non-target crustaceans.”
Rosa H. Escobar Lux, PhD candidate,
Research group Disease & Pathogen 
Transmission.Havforsknings Institute 
of Marine ResearchAustevoll Research Station, 
Norway.

I interviewed the lead author of the study, Rosa Escobar Lux (l.).

PinP: Do you have any evidence that the abundance of Calanus spp. may be affected to the degree that the fish themselves are becoming "food-deprived?" 

Dr. Escobar Lux: "No. Our experiments were done in a laboratory which can answer some of our questions but it does not give definite answers to what is happening in the wild.  Also, there's a need for dispersion models to help us understand the real magnitude of the effects...."

The findings of her team were published recently in the Canadian science journal, FACETS.


Is evidence of harm confined to the lab?

Another study from Norway published just last month,  takes us beyond the lab, into open waters (or "the wild" as Dr. Escobar Lux puts it). It reveals, elevated levels of the pesticide diflubenzuron (DFB) are being found in commercially-valuable northern shrimp, (Pandalus borealisin Norwegian fjords. Salmon farms there use a medicated feed containing that productLab tests have shown it can be lethal to the shrimp, and actually becomes more toxic in warmer waters. This raises added concerns in a world that is heating up fast.

Many Norwegian fishers report, they're catching fewer shrimp in fjords where salmon farms are operating. Experts want further studies to find out if shrimp populations are already crashing. 

And yet another recent study reaches a similar conclusion, that 
hydrogen peroxide's toxicity may already be making itself felt in the open ocean, on northern shrimp. Conducted by mostly Norwegian researchers, they find hydrogen peroxide may be causing "gill damage and delayed mortality" to the shrimp, more than a kilometre from fish farms there.

But, there's more. Even older studies, some done in Canada, point to several other marine creatures being vulnerable to aquacultural pesticides, too. These not only include zooplankten like the kind already referred to, but commercially valuable catches such as lobster and shrimp!

Last year, experts "rounded up" those studies and combined them in  a single, "systematic and exhaustive" review. 

They concluded that hydrogen peroxide wasn't the only suspect product. Three others, cypermethrin, deltamethrin and azamethiphos - each used extensively in the industry - had similar effects. 

The review concludes, "Aquaculture has consequences for the environment. Salmon and trout cage culture has required the use of large quantities of pharmaceuticals. Our results show clear negative  effects at concentrations lower than those used in treatments against sea lice in all of the species studied." 

Despite all of this, in 2016, quite some time after much of this research was known,  Health Canada granted "full registration for  the sale and use" of pesticides using hydrogen peroxide as their active ingredient" for the treatment of sea lice on Atlantic salmon reared in marine aquaculture sites." That was at least five years after the first warnings about the pesticides I was personally able to findwarnings that our government officials must have been aware of. 

A year later, the Department registered also azamethiphos for an identical use, giving identical reasons for doing so. 

In its documents approving registration of both products, Health Canada concludes, "Under the approved conditions of use, the products have value and do not present an unacceptable risk to human health or the environment.   relatively benign products that pose little or no risk to salmon, the marine environment, non-target species, or human health." 

It went on to recommend that the industry, facing one of its worst years for sea lice that year, be allowed one treatment more of H202 than was usually allowed. 

In addition to H202, Canada has, for at least a decade, also permitted the use of deltamethrin, at least in Atlantic Canada.  Cypermethrin, however, is prohibited. 


In the course of my investigation, I was only able to find out how much hydrogen peroxide is being used in aquaculture.

Health Canada figures (see table) show more than one million kilograms were sold in 2016. That placed the active ingredient among the top ten best-sellers that year (9th). It did not register in the top ten the following year. (The government counts products sold for aquaculture as "agricultural.")


Top 10 Active Ingredients Sold in Canada in 2016 in the Agricultural Sector

Active Ingredient 
Product Type
Glyphosate
Herbicide
Surfactant blend
Other
Available chlorine, present as sodium hypochlorite 
Antimicrobial
Glufosinate ammonium
Herbicide
2,4-D
Herbicide
MCPA
Herbicide
Mineral oil
Insecticide/Fungicide/Other
Mancozeb
Fungicide
Hydrogen peroxide
Herbicide/Insecticide/Fungicide
Chlorothalonil
Fungicide
Source - PMRA - Health CA. 


If that figure sounds high, amounts used in Norway - the world's largest producer of farmed Atlantic salmon - are "through the roof" by comparison. One source says, the industry in that country applied 132 million kilograms of H202 between 2009 and 2018. That would be at least than 13 times more per year than the Canadian usage!

So why do regulators continue to register these products?


The importance of aquaculture to human society is widely recognized. In their own studies, the researchers describe it as "One of the best prospects to help meet the growing need for protein in the human diet." 

The UN's Food and Agriculture Organization estimates, almost 19 million people worked in that sector in 2015. The world now produces about as much farmed fish as that taken in the wild. Once non-fish products (plants, shells and pearls) are added in - more than 100 million tonnes, or US$163 billion dollars worth of products, were produced by "ocean-farming" that year. It's considered the fastest-growing source of food for human consumption and is made up mostly of "finfish" such as the Atlantic salmon.


In Canada, government figures show, aquaculture employed 14 thousand people, full-time in 2009. For some reason, it's the most recent figure available. In 2013, production in the sector was valued at almost $1 billion. This country is ranked as the world's 4th-largest producer of farmed salmon. 

The website of the Canada Food Inspection Agency proudly states:

"Canada is one of the world's most trusted and respected food suppliers, trusted to provide safe and wholesome products and respected for our commitment to global food security. Canada's strong regulatory system forms the basis of this positive reputation."  (Emphasis mine.)


Are there better ways?

Researchers with Fisheries and Oceans Canada are among those looking for alternatives. They're trying to find out whether physical light traps and biological filters may be able to attract and remove the sea lice from the farms. There's no sign, yet that such methods are about to replace that heavy pesticide use, however. 

Meanwhile, research published about five years ago, seems to put an even finer point on the importance of finding alternatives - not just to pesticides - but to aquaculture itself!  Growth of the industry could actually be worsening the problem. Since sea lice numbers are proportional to fish size, "expanded salmon farming has shifted the conditions in favour of the parasites. Salmon farms are often situated near migrating routes of lice in the open ocean." 

And, as if that weren't enough, the lice are now showing resistance to three of the five compounds being used against them.

On January 11th, I e-mailed Canada's Minister of Health, Patty Hajdu (responsible for the Pesticide Management Regulatory Agency); Fisheries and Oceans Minister, Bernadette Jordan and the "Canadian Aquaculture Industry Alliance," to comment on my story. 


Apart from automated, return e-mails promising mine would be reviewed, at this writing, I've received no responses.



-30-


Saturday, 18 January 2020

Like Adding'Five to Six Hiroshima Bombs of Heat Each Second,' Study Shows Oceans Warming at Record Rate


CommonDreams
"If you want to understand global warming, you have to measure ocean warming." Story here.



Saturday, 7 December 2019

Marine life, fisheries increasingly threatened as the ocean loses oxygen – IUCN report


International Union for the Conservation of Nature
The Daggernose shark, one of several larger species
considered especially vulnerable. A NOAA rendering.
The loss of oxygen from the world’s ocean is increasingly threatening fish species and disrupting ecosystems, a new IUCN report warns. Ocean oxygen loss, driven by climate change and nutrient pollution, is a growing menace to fisheries and species such as tuna, marlin and sharks, according to the report released today at the UN Climate Change conference in Madrid.

Monday, 18 November 2019

Study counts 1.8 million pieces of trash at the bottom of Canada's Bay of Fundy


The National Observer

Daniels Flat (Bay of Fundy)


A survey estimates more than 1.8 million pieces of garbage are strewn over the bottom of the Bay of Fundy, prompting concerns about potential harm to marine life. Story here.

Wednesday, 13 November 2019

Microplastics found in oysters, clams on Oregon coast, study finds. (Last year, Canadian scientists discovered high levels of microplastics in B.C.’s oyster beds). Is our clothing to blame?


EurekAlert
Pacific oysters, farmed in the U.S.
Photo by NOAA.
Tiny threads of plastics are showing up in Pacific oysters and razor clams along the Oregon coast -- and the yoga pants, fleece jackets, and sweat-wicking clothing that Pacific Northwesterners love to wear are a source of that pollution, according to a new Portland State University study. Story here.

RELATED:

Friday, 1 November 2019

The Amazon River: A Major Source of Organic Plastic Additives to the Tropical North Atlantic?


Environmental Science & Technology
The Amazon empties into the Atlantic.
"Flick" Coordenação-Geral de Observação da Terra/INPE
Dissolved surface water concentrations of two important families of plastic additives were found in remarkably high concentrations in the Amazon river plume. Story here.


Why fish ARE getting smaller (Video)

Vid

Tuesday, 22 October 2019

Ban oil, gas, bottom trawling in CANADA'S marine protected areas, panel urges


THE STAR
Image by NOAA.
-->
A panel that has spent the year studying marine protected areas (MPAs) in Canada says no oil and gas development, seabed mining, or bottom-trawling fishing should be allowed within their boundaries.
More here.

RELATED:
New research finds that “marine reserves” – tracts of ocean where fishing is banned – are protecting fish, the coral reefs where they live and vast undersea "gardens," a lot more than once thought. By Larry Powell.

Wednesday, 7 August 2019

Industrial fishing behind plummeting shark numbers


Science News
Research finds marine predators are significantly smaller and much rarer in areas closer to people. Story here.
An ocean "white-tip" shark. Photo by NOAA.

Tuesday, 16 July 2019

Thirty years of unique data reveal what's really killing coral reefs


Science News
Study is world's longest record of reactive nutrients, alga concentrations for coral reefs. Story here.
Bleached coral. Photo by NOAA.


Friday, 21 June 2019

Canada becomes first G7 country to ban shark fin imports

The Guardian

Shark fins for sale in Canada.
Photo by Hakai MAGAZINE 
  • Measure which also bans sale of fins awaits royal assent. Story here.

Thursday, 2 May 2019

New research finds that “marine reserves” – tracts of ocean where fishing is banned – are protecting fish, the coral reefs where they live and vast undersea "gardens," a lot more than once thought.

Large-scale commercial fishing has, for years, been depleting fish-stocks in many places around the world - especially in coral reefs in the tropics. In response, several countries have designated certain areas of the sea as "marine reserves," where neither fishing nor other development is allowed. Now, a team of scientists from US and Australian universities has produced compelling new evidence. It shows these reserves have not only been helping stocks rebound, but are also protecting massive coral "food webs" - beds of sea-grasses and algae - important reservoirs for carbon storage. 
by Larry Powell
In this satellite photo, "halos" appear as pale blue circular bands 
surrounding tiny dark spots.The spots are likely small patch reefs 
or other shelter for small fish and invertebrates that protect them 
from predators. Each halo is probably about 10 meters wide. 
The more there are, the healthier marine life there is likely to be.
Using hi-rez images from both satellites and underwater cameras, the researchers studied hundreds of small, tropical reefs in the huge Great Barrier Reef complex off Australia. 

Those images detected about two-&-a-half times more halos within the reserves than elsewhere. The more halos, the healthier the reef is considered to be as a home for both fish and invertebrates. 

These pale blue, circular bands surrounding the small dark spots, are where herbivorous, or plant-eating fish and some marine mammals, venture out to graze on surrounding vegetation such as algae or seagrass. Then, they dart back in, using the reefs as protection from the predators. 

The scientists refer to the halos as "seascape-scale footprints" of healthy, increased activity in aquatic life.
Elizabeth M.P. Madin, Ph.D.
Assistant Research Professor
Hawaii Institute of Marin Biology
University of Hawaii at Manoa, USA.
The spokesperson for the study, Dr. Elizabeth Madin (above), tells PinP, "What the halos are telling us is that marine reserves - especially older ones - where predator and herbivore populations have had sufficient time to recover from previous fishing - are protecting key species and their resulting interactions.


"Specifically," she adds, "we’re more likely to see halos in especially older reserves (40 years old or so), which suggests that predators and prey are in sufficient numbers there to interact and cause these halo patterns." 

Since halos can also be found in some ares unprotected from fishing, the team calls for more research to further confirm the connection.

Among groups funding the research were the World Wildlife Fund and the US National Science Foundation.

The findings were published recently in the proceedings of The Royal Society in the UK and in Frontiers in Ecology and Evolution.  


But the benefits of marine reserves, don't stop here.

"Importantly," Dr. Madin goes on, "we know from another of our studies, that halos affect carbon storage. So, not only are marine reserves re-shaping coral reef landscapes on very large scales in ways we didn’t know about before, but they’re also affecting a key ecosystem service - carbon storage."

She's referring to a truly fascinating undersea scenario in which predator fish actually play a beneficial - albeit indirect - role in carbon sequestration. A healthy habitat means more predators. Their prey, often herbivorous fish or marine mammals, cling to the relative safety of their home reefs and don't venture too far afield to find plants to eat. 

Dugongs, a type of marine mammal, are
known to be capable of decimating sea-grass beds
as they graze. Photo taken in an oceanarium in Jakarta.

This spares massive sea-scapes of algae and sea-grasses nearby, which would otherwise be stripped by the plant-eaters. Instead, the vegetation grows taller and denser, greatly increasing its capacity to store carbon, thus providing a significant buffer against climate change.

Not only are the number of marine reserves growing, worldwide, they're getting bigger, too (some more than 100 thousand km2). Nineteen of these "mega-reserves" have been established since 2009. And happily for the sea-life living there, the research finds, the bigger the reserves, the more protection they offer!

Beyond Covid 19. Are we risking yet another pandemic if we continue to embrace "assembly-line" livestock production into the future?

by Larry Powell No one would argue that Covid 19 demands our undivided attention. Surely,  defeating this "beast" has to be &...