In September, there were 29 blog posts covering PLoS ONE papers aggregated on ResearchBlogging.org. There were many wonderful posts, which made it difficult for us to narrow it down to one. Though difficult, we decided the winner for this month is…
His post describes a recent PLoS ONE article entitled, Evidence for a Novel Marine Harmful Algal Bloom: Cyanotoxin (Microcystin) Transfer from Land to Sea Otters by authors Melissa Miller, Raphael M. Kudela, Abdu Mekebri, Dave Crane, Stori C. Oates, Timothy Tinker, Michelle Staedler et al.
From the Abstract of the paper:
“Super-blooms” of cyanobacteria that produce potent and environmentally persistent biotoxins (microcystins) are an emerging global health issue in freshwater habitats. Monitoring of the marine environment for secondary impacts has been minimal, although microcystin-contaminated freshwater is known to be entering marine ecosystems. Here we confirm deaths of marine mammals from microcystin intoxication and provide evidence implicating land-sea flow with trophic transfer through marine invertebrates as the most likely route of exposure. This hypothesis was evaluated through environmental detection of potential freshwater and marine microcystin sources, sea otter necropsy with biochemical analysis of tissues and evaluation of bioaccumulation of freshwater microcystins by marine invertebrates. Ocean discharge of freshwater microcystins was confirmed for three nutrient-impaired rivers flowing into the Monterey Bay National Marine Sanctuary, and microcystin concentrations up to 2,900 ppm (2.9 million ppb) were detected in a freshwater lake and downstream tributaries to within 1 km of the ocean. Deaths of 21 southern sea otters, a federally listed threatened species, were linked to microcystin intoxication. Finally, farmed and free-living marine clams, mussels and oysters of species that are often consumed by sea otters and humans exhibited significant biomagnification (to 107 times ambient water levels) and slow depuration of freshwater cyanotoxins, suggesting a potentially serious environmental and public health threat that extends from the lowest trophic levels of nutrient-impaired freshwater habitat to apex marine predators. Microcystin-poisoned sea otters were commonly recovered near river mouths and harbors and contaminated marine bivalves were implicated as the most likely source of this potent hepatotoxin for wild otters. This is the first report of deaths of marine mammals due to cyanotoxins and confirms the existence of a novel class of marine “harmful algal bloom” in the Pacific coastal environment; that of hepatotoxic shellfish poisoning (HSP), suggesting that animals and humans are at risk from microcystin poisoning when consuming shellfish harvested at the land-sea interface.
In Southern Fried Scientist’s post, he says:
Several factors are in play here. The first and most obvious is that biological systems are connected. Problems with freshwater systems don’t just affect freshwater systems, marine ecosystems are not separate from freshwater ecosystems. Second, the cause of disease isn’t always obvious – before 1946 no one even knew that blue-green algae blooms were toxic, and even then no one though they were affecting marine ecosystems. This is, in fact, the first case of microcystin infecting a marine mammal. Finally, establishing a mechanism for uptake is essential for determining the underlying cause and designing a mitigation scheme.
We will be notifying Southern Fried Scientist and the authors of the article and send them the famous PLoS ONE t-shirts as prizes. This month’s runner-ups are: Sean Roberts, Brian Switek, and Andrew Farke.
A big thanks goes out to everyone who wrote about a PLoS ONE paper this month! We love reading your posts and we’re already on the lookout for October’s Blog Pick of the Month.
March 2009: Ed Yong April 2009: Eric Michael Johnson May 2009: Christie Wilcox June 2009: Iddo Friedberg July 2009: Toaster Sunshine Hermitage August 2009: Bjoern Brembs September 2009: Alun Salt October 2009: Andrew Farke November 2009: John Beetham December 2009: SciCurious January 2010: Anne-Marie Hodge February 2010:Princess Ojiaku March 2010: Grrrlscientist April 2010: Jason Goldman May 2010: Brian Switek June 2010: Greg Laden July 2010: Hannah Waters and August 2010: EcoPhysioMichelle