Saving Seafood

Study Finds Growing Potential for Toxic Algal Blooms in the Alaskan Arctic

October 6, 2021 — Changes in the northern Alaskan Arctic ocean environment have reached a point at which a previously rare phenomenon—widespread blooms of toxic algae—could become more commonplace. These blooms potentially threaten a wide range of marine wildlife and the people who rely on local marine resources for food. That is the conclusion of a new study about harmful algal blooms of the toxic algae Alexandrium catenella published in the journal Proceedings of the National Academy of Science. Microscopic algae in the ocean are most often beneficial and serve as the base of the marine food web. However, some species produce potent neurotoxins that can directly and indirectly affect humans and wildlife. 

Dormant Cysts Could Seed a Toxic Bloom

The study was led by scientists at the Woods Hole Oceanographic Institution (WHOI) in collaboration with colleagues from NOAA’s Northwest Fisheries Science Center and researchers in the United States, Japan, and China. It looked at samples from seafloor sediments and surface waters collected during 2018 and 2019. Samples were taken in the region extending from the Northern Bering Sea to the Chukchi and Beaufort Seas north of Alaska. The sediment samples allowed the researchers to count and map Alexandrium cysts. The cysts are a seed-like resting stage that lies dormant in the seafloor for much of the year, germinating or hatching only when conditions are suitable. The newly hatched cells swim to the surface and rapidly multiply using the sun’s energy. This produces a “bloom” that can be dangerous due to the family of potent neurotoxins, called saxitoxins, that the adult cells produce.

When the algae are consumed by some fish and all shellfish, those toxins can accumulate to levels that can be dangerous to humans and wildlife. In fish, toxin levels can be high in digestive and excretory organs (e.g., stomach, kidney, liver), but are very low in muscle and roe.  Although fish can be potential toxin vectors, the human poisoning syndrome is called paralytic shellfish poisoning. Symptoms range from tingling lips, to respiratory distress, to death. The toxin can also cause illness and death of marine wildlife such as larger fish, marine mammals, and seabirds. This is of particular concern for members of coastal communities, Alaskan Native Villages, and Tribes in northern and western Alaska who rely on a variety of marine resources for food.

Read the full article at NOAA Fisheries

 

 

Harmful algal blooms can be lethal for humans. Scientists wonder if they cause seabird die-offs, too

July 29, 2021 — Paralytic shellfish poisoning, caused by eating seafood contaminated with toxins from harmful algal blooms, can be deadly to humans. Now, using marine samples from Unalaska, scientists are trying to understand if those harmful algal blooms could also be responsible for seabird die-offs.

There’s not much data on how saxitoxin — a harmful compound produced by algal blooms that cause PSP — spreads through the larger food web. But in July, a group of biologists with the United States Geological Survey visited Unalaska to collect samples of plants and animals in hopes of learning more about how saxitoxin levels magnify and diminish as they move through the food chain, from phytoplankton to mussels and up to seabirds.

“We don’t really know how this toxin moves through the food web,” said Sarah Schoen, a USGS wildlife biologist that recently collected marine samples in Unalaska. “There’s still a lot of unknowns, but the more information we can collect about it, the more we’ll understand it.”

Schoen said the project started about five years ago when a major heat wave, known as “the blob,” hit the ocean. Around the same time, there was a die-off of an estimated million common murres — a northern seabird — from Alaska down to California.

Read the full story at KTOO

WHOI receives NOAA awards to study, predict harmful algal blooms

October 7, 2020 — The following was released by the Woods Hole Oceanographic Institution:

Researchers at Woods Hole Oceanographic Institution (WHOI) were recently named in a list of 17 new research projects funded by the National Oceanic and Atmospheric Administration (NOAA) to improve the nation’s collective response to the growing problem of harmful algal blooms (HABs). The four projects led, co-led, or supported by WHOI researchers total nearly $2.5 million over the coming year and $7.9 million over the course of the projects. A full list of the new grant awards is available online and includes projects funded under NOAA’s National Centers for Coastal Ocean Science (NCCOS) and the  U.S. Integrated Ocean Observing System (IOOSⓇ) Office.

“NOAA is funding the latest scientific research to support managers trying to cope with increasing and recurring toxic algae that continue to affect environmental and human health of coastal communities,” said David Kidwell, director of NOAA’s National Centers for Coastal Ocean Science (NCCOS) Competitive Research Program. “These projects will address the largely unknown socioeconomic impact of blooms in various regions, improve local managers’ ability to keep drinking water safe, aid monitoring for algal toxins in seafood and advance a potentially valuable control method for Florida red tide and other blooms, enhancing our nation’s collective response to these events.”

Marine and fresh waters teem with life, much of it microscopic, and most of it harmless. Although most of these phytoplankton and cyanobacteria are harmless, there are some that create potent toxins and, under the right conditions, both toxic and non-toxic species can form blooms that threaten the health of humans and ecosystems, and cause significant societal and economic problems.

These impacts include human illness and death following consumption of or indirect exposure to HAB toxins, economic losses to coastal communities and commercial fisheries, and HAB-associated wildlife deaths. Freshwater HABs can also affect drinking water supplies far from the ocean and are a growing problem as water temperatures rise, precipitation patterns change, and the use of agricultural fertilizers becomes more widespread.

Read the full release here

NOAA Awards $1.7M For Harmful Algal Bloom Research To Protect Public Health From Toxins In Shellfish

Multi-year awards to focus on bloom prevention in seven states

September 20, 2017 — NOAA has announced nine research grants will go to organizations around the country seeking to better understand and measure the toxicity of harmful algal blooms, known as HABs.

In the first year, $1.68M will fund research for projects in Alaska, California, Florida, Maine, Maryland, Ohio and Virginia. The grants are administered by NOAA’s National Centers for Coastal Ocean Science.

NOAA funding enhances state and regional monitoring with advanced harmful algae detection capabilities, including shellfish toxin tests. (Credit: Washington State Department of Ecology Marine Monitoring Unit)

Grant recipients will conduct research to identify conditions that increase a bloom’s toxicity; model toxin movement from the water into shellfish, fish and marine mammals; and improve toxin monitoring and forecasts. The dense scum, strong odors and toxins produced by HABs can contaminate drinking water, trigger fisheries closures and disrupt tourism.

Read the full story at Water Online

With droughts and downpours, climate change feeds Chesapeake Bay algal blooms

August 11, 2016 — Nitrogen-rich agricultural runoff into the Chesapeake Bay presents an ongoing environmental and economic concern for the bay’s massive watershed. Pollution from fertilizer application feeds algal blooms that poison humans and marine life, and devastate fisheries.

 While efforts to restore the bay have been successful during the past several years, a study led by Princeton University researchers shows that weather patterns tied to climate change may nonetheless increase the severity of algal blooms by changing how soil nutrients leach into the watershed.

Extreme rainfall cycles caused by increased climate variability flush larger amounts of nitrogen-containing nutrients from fertilizer and other sources into the Susquehanna River, which carries them into the Chesapeake Bay, according to a report in the journal Geophysical Research Letters. Moreover, a spike in rainfall can increase nitrogen levels in the bay even if the amount of fertilizer used on land remains the same.

These chemicals feed explosive algae growth that can produce toxins that harm people, fish, wildlife and drinking water. Decaying algae also suck oxygen from the surrounding water, creating a low-oxygen state known as hypoxia that results in “dead zones” that suffocate fish and other species important to the aquatic food chain.

The researchers constructed a model that they say provides the most complete picture to date of how nitrogen moves from place to place in the Chesapeake Bay watershed. It connects weather and pollution in places as far away as upstate New York to the water conditions in the bay.

Read the full story at Phys.org