Tag Archives: lake

Sea otters helped by artificial clams

iStock_000032380552SmallIn the last five years, 24 sea otters have stranded and died in the Monterey Bay area. Veterinarians noticed a strange yellow coloration to the animals, so they performed necropsies and determined that the cause of death was something pretty unexpected- microcystin.

Microcystin is a cyanotoxin produced by algae, and because it’s generally found in freshwater, deaths in ocean mammals are particularly troubling. Investigation led researchers to a nearby freshwater lake, where they used ‘artificial clams’- small bags of polystyrene beads- to give them some answers. The bags can be left in the water for periods of time, and much like real clams, they passively absorb toxins. Later, they can be analyzed to determine toxin levels over a period of time.

Researchers confirmed that the lake was the source of the problem. They found that a combination of natural phosphorous in the underlying rock combined with chemical runoff from local agriculture created the perfect environment for the algae that produces microcystins. When the lake water fed into the ocean, invertebrates such as clams and mussels in the ocean collected the toxin and concentrated it. When sea otters fed on the toxic clams, they were slowly poisoned.

They’ve found the source, but now it’s a question of how to address it. Researchers are working on potential treatments for microcystin poisoning (with the help of rats!), and hopefully, this will lead to treatments that can help marine animals as well as humans.

http://www.the-scientist.com//?articles.view/articleNo/39864/title/Sea-Otter-s-Scourge/

Family dog saved… by rats!

Levi by Lake JacksonAnnabelle, an Australian Shepherd, was spending time with her family at a Montana lake when disaster struck. As they were heading to the shore, Annabelle jumped out of the boat, swam to shore, and in the process of drying off, she licked her wet fur. This is a pretty normal thing for a dog to do, but this time, it almost turned deadly. 

When fertilizers or other organic nutrients enter lakes and streams, it can result in large blooms of blue-green algae called cyanobacteria. Unfortunately, cyanobacteria living in this particular lake had produced a liver toxin called microcystin, and after Annabelle ingested it, she quickly became sick. Her veterinarian rushed to find something that could save her life.

Cholestyramine, a drug that had worked against this type of poisoning in rats, was suggested. It had never been tested in dogs, but Annabelle had no other option- without some type of treatment, she would die.

After her vet administered the drug, Annabelle started improving the very next day! Researchers hope that results in one species will give them an indication of the way other species will react to the same drug or treatment. Fortunately for Annabelle, this was a case where rats and dogs had the same type of reaction to this particular treatment, and without those rats, Annabelle wouldn’t have survived. Read more about it here:

http://www.the-scientist.com/?articles.view/articleNo/39760/title/Dog-s-Worst-Friend/