SeaDoc Blog
What's the Deal with Rockfish and Seals?
Harbor seal populations have exploded nearly tenfold in the Salish Sea since the 1970s, while at the same time many rockfish species have plummeted. Some fishermen blame that on the increase in hungry seals. But coincidence is not science. So who ya gonna call?
In the second year, 12% of the samples contained rockfish remains, particularly in the winter when there are fewer salmon locally. With all the seals in the Salish Sea, those numbers could impact rockfish recovery. That doesn't mean, however, that we should start controlling seal populations: this study showed seals also have a taste for dogfish, another major fish predator. So fewer seals could mean more dogfish. The real answer is to remember that all parts of our ecosystem are tightly intertwined. Rockfish recovery depends upon ecosystem recovery, including salmon recovery, herring recovery and so on around the Sea.
More information on this topic:
- The original report on this study (so you can see what we've learned since the first round)
- The Puget Sound Partnership's resource page on rockfish.
- SeaDoc's comments on the proposed (12/2009) rockfish conservation plan by the WA Dept of Fish & Wildlife.
- All the info on our site about rockfish (automatic search)
- All the info on the site about predator/prey relationships (automatic search)
(You can do these last two searches yourself by choosing "browse by species" or "browse by issue" from the Salish Sea menu at left.)
2009 State of the Sound Report released
The Puget Sound Partnership just posted the 2009 State of the Sound Report.
Every 2 years the Partnership publishes this to document the current status of the ecosystem and to update people on what is being done. It also details what was accomplished during the prior 2 years and presents an overview of funding and anticipated results for 2009-2011. Through its various science projects and science translation efforts, SeaDoc provides information and guidance for these reports.
The entire report is at:
www.psp.wa.gov/sos2009.php
Killing with kindness: birdfeeder associated diseases in wild birds
Birding is the one of the leading recreational past times in the United States. In addition to the popularity of bird viewing and species identification, millions of people actively and purposefully attract wild birds to their homes and yards with bird feeders. Commonly encountered species at bird feeders are primarily passerines, and those that are resident in an area may use feeders year- round, especially in winter when weather is harsh and other sources of food are difficult to access. Types of feeders vary from the common tube-shaped seed or nectar feeders, to platform-type structures that hang or sit on a post or on the ground. Feeders are stocked with sunflower seeds, millet, cracked corn, thistle, peanuts, sugar solution, or suet.
Bird feeders can be an important source of nutrition for birds, especially during abnormal or harsh climate or foraging conditions, yet they are man-made constructs and therefore an artificial habitat, promoting repeated congregation of multiple species of birds around a point source of food. Not only may this result in unnatural densities of birds at a given point in time, it can also lead to interactions among and between species that would normally not occur.
PREVENTING DISEASE TRANSMISSION AT BIRD FEEDERS
Keeping bird feeders clean and using fresh food, unused portions of which are changed out regularly, are keys to preventing disease transmission at bird feeders. Feeders should be cleaned at least once a week with 10% bleach solutions. The ground under and around feeders should be swept to remove droppings and unused feed. Water in drinkers or baths should be changed daily.
The type of feeder used has implications for disease transmission as well. Tube feeders that do not accumulate bird droppings the way that platform feeders do may be beneficial in this regard, although studies have shown that tube feeders promote direct contact between birds competing for the limited access points.
To prevent zoonotic potential, people should wear rubber gloves when cleaning. Keeping cats indoors during feeder-associated outbreaks is important for the health of the cats and their owners. During outbreaks of mycoplasmosis or salmonellosis, people should be urged to stop using bird feeders until the epidemic resolves.
Download the complete PDF from which these excertps were taken.
Kirsten V.K. Gilardi, DVM, DACZM School of Veterinary Medicine University of California, Davis, CA
Six presentations by Joe Gaydos & Kirsten Gilardi at the 2010 North American Veterinary Conference
In January 2010, Joe Gaydos and Kirsten Gilardi gave six presentations at the North American Veterinary Conference. Kirsten Gilardi chaired the session on wildlife health.
(Each of the linked PDFs are just a few pages in length, and not overly technical. They're worth a read.)
Gaydos, Joseph K. 2010. Rabies redux: a review of rabies and other critical wildlife zoonoses. Proceedings of the 2010 North American Veterinary Conference, Orlando, FL, January 2010:1812-1814.
Gaydos, Joseph K. 2010. Deer downtown: urban deer disease and management. Proceedings of the 2010 North American Veterinary Conference, Orlando, FL, January 2010: 1815-1817.
Gaydos, Joseph K. 2010. Urban Orca: killer whales in Puget Sound. Proceedings of the 2010 North American Veterinary Conference, Orlando, FL, January 2010: 1818-1820
Gaydos, Joseph K. 2010. Injured wildlife at your door: knowing when to euthanize. Proceedings of the 2010 North American Veterinary Conference, Orlando, FL, January 2010: 1821.
Gilardi, Kirstin V. K. 2010. Killing with kindness: birdfeeder associated diseases in wild birds. Proceedings of the 2010 North American Veterinary Conference, Orlando, FL, January 2010: 1822-1824.
Gilardi, Kirstin V. K. 2010. Wildlife Top 10 in 2010: hot topics, new challenges and promising solutions. Proceedings of the 2010 North American Veterinary Conference, Orlando, FL, January 2010: 1825-1827.
SeaDoc seeks PostDoc for marine bird research
The SeaDoc Society seeks a post-doctoral scientist to lead an international collaborative effort investigating status and trends of marine bird populations in the Salish Sea.
Gray-colored transient killer whale spotted
Ocean Zoning may help killer whales
Scientists in Scotland, Canada and the US have proposed a new method to identify priority areas for whale conservation. The team's findings, published in Animal Conservation, suggest that even small protected areas, identified through feeding behaviour, can benefit highly mobile marine predators such as killer whales.
"Zoning the ocean is a new concept and is rife with human conflict," said Dr Joe Gaydos, science advisor to Puget Sound Partnership and Chief Scientist for the SeaDoc Society. "Science is our most objective tool for balancing species recovery and human needs and work like [lead author] Ashe's is critical if we're going to ask boaters and fishermen to leave important areas for the whales."
Read more:
http://www.wildlifeextra.com/go/news/whale-protection.html#cr
http://www.eurekalert.org/pub_releases/2009-12/w-zto121409.php
Your best friend may not be so eco-friendly
Disturbing results came from a site in south Puget Sound where seals were not only infected with their own brand of Giardia, but also with a canine variety, which shows that diseases from our pet dogs are being transmitted to marine wildlife. Future studies will tell us what effect the dog Giardia is having on the seals, but for now it's an important wake-up call and reminder for everyone who cares about the oceans: The land and sea are intimately connected and even doing simple things like scooping your best friend's poop will help keep the ocean and its wildlife healthy.
More Images from 2009 Photo Contest
Here's a slideshow of a few of the best runner-up images from the 2009 Underwater Photo Contest:
Chance to comment on fishing regulations
The Washington Department of Fish and Wildlife is accepting comments on their proposed fishing rules for the 2010-2012 seasons. Unlike in the past, these regulations will cover a two year period.
Comments are accepted until 12/1/09.
Based on the scientific work we've been doing over the past decade, SeaDoc has important comments on the proposed rules.
Here's background on the general rule changes:
http://seattletimes.nwsource.com/html/reeltimenorthwest/2010219339_state...
You can download Joe Gaydos's formal comment submission here.
Make your own comments at http://wdfw.wa.gov/fish/regs/rule_proposals/index.htm