An estimated 1.2 million cases of salmonellosis occur annually in the United States (approximately 42,000 are laboratory-confirmed and reported to the Centers for Disease Control; CDC). Transmission comes primarily from contaminated food, water or contact with infected animals only some of which are wild animals. Of the 50 Salmonella outbreaks reported by the CDC between 2006 and 2013, only 5 (10%) were related to wildlife. These included the 2013 outbreak related to small turtles (Salmonella Sandiego, Pomona and Poona), two 2012 events associated with hedgehogs (Salmonella Typhimurium) and small turtles (Salmonella Sandiego, Pomona and Poona), the 2011 outbreak connected to Africa dwarf frogs (Salmonella Typhimurium) and the 2010 water frog-related outbreak (Salmonella Typhimurium).
Leatherback turtles (Dermochelys coriacea) are critically endangered, primarily threatened by the overharvesting of eggs, fisheries entanglement, and coastal development. The Pacific leatherback population has experienced a catastrophic decline over the past two decades. Leatherbacks foraging off the coast of California are part of a distinct Western Pacific breeding stock that nests on beaches in Indonesia, Papua New Guinea, and the Solomon Islands. Although it has been proposed that the rapid decline of Pacific leatherback turtles is due to increased adult mortality, little is known about the health of this population. Health assessments in leatherbacks have examined females on nesting beaches, which provides valuable biological information, but might have limited applicability to the population as a whole. During September 2005 and 2007, we conducted physical examinations on 19 foraging Pacific leatherback turtles and measured normal physiologic parameters, baseline hematologic and plasma biochemistry values, and exposure to heavy metals (cadmium, lead, and mercury), organochlorine contaminants, and domoic acid. We compared hematologic values of foraging Pacific leatherbacks with their nesting counterparts in Papua New Guinea (n=11) and with other nesting populations in the Eastern Pacific in Costa Rica (n=8) and in the Atlantic in St. Croix (n=12). This study provides the most comprehensive assessment to date of the health status of leatherbacks in the Pacific. We found significant differences in blood values between foraging and nesting leatherbacks, which suggests that health assessment studies conducted only on nesting females might not accurately represent the whole population. The establishment of baseline physiologic data and blood values for healthy foraging leatherback turtles, including males, provides valuable data for long-term health monitoring and comparative studies of this endangered population.
Lost fishing gear is commercial and recreational fishing gear — nets, traps, pots, line — that becomes lost or is discarded in the water.
The gear ends up sitting on the sea floor, getting caught on rocky reefs, or floating in the water column.
The majority of this lost gear does not decompose in seawater and can remain in the marine environment for years.
Lost gear impacts the marine environment in several ways:
- it can continue to "catch" marine animals, which become entangled or trapped;
- it can damage the habitat upon which it becomes entangled or upon which it rests;
- it can pose an underwater hazard for boaters, entangling boat propellers and anchors;
- and it can similarly endanger humans, especially divers.
Lost gear is also a visual blight, diminishing the natural aesthetic quality of the seafloor and rocky reef habitat for underwater enthusiasts.
SeaDoc works on derelict fishing gear in California and in the Salish Sea.
Our executive director, Kirsten Gilardi, runs the California Lost Fishing Gear Recovery Project out of the Wildlife Health Center offices at the UC Davis School of Veterinary Medicine. (Dr. Gilardi is also co-director of the Mountain Gorilla One Health Project and the Envirovet Summer Institute.)
SeaDoc provides technical assistance and support for derelict gear removal in the Salish Sea. We have worked closely with the Northwest Straits Commission to analyze data from recovered nets to determine the economic impact of lost gear and its removal.
The results showed a clear return on investment for removing nets. For example, we calculated that an abandoned net might kill almost $20,000 worth of Dungeness crab over 10 years. Cost to remove? $1,358.00.
Click here to learn more about the economic impact of derelict gear.
Photos by Jen Renzullo. Video by Mike Neil.