I participated in an investigation of sliders dying on Wapato Lake in Tacoma. Several were collected and submitted to Northwest Zoopath for necropsy and pathology examination. The occurrence of sick and dead turtles overlapped with deaths of birds on the lake, primarily mallards. The diagnosis for the mallards submitted to the WSU Avian Health Lab was botulism. However, there was a toxic algae bloom at Wapato Lake during this time period as well. It all seemed to boil down to a very sick aquatic system with anoxic conditions, in places, and toxic algal blooms reflective of high nutrient levels from urban run-off and, possibly, atmospheric deposition. Sliders may also be poorly adapted to our climate and therefore more vulnerable to a variety of stressors. Slder die-offs on Lake Washington and at least one other King County lake, are nothing new. It's just that no one invests resources into determining why (And, even if you do invest in necropsies and histological work, definitive answers can be very elusive).

I've always marvelled at the large number of sliders present in Lake Washington. As far as I can tell, there is not a single record of a successful hatching of slider eggs at our latitude. The turtles clearly lay fertile eggs but no one tracks the nests to determine success and small sliders, indicative of successful reproduction, are never seen (in my experience). It's been suggested that the entirety of Lake Washington's slider numbers is supported by repeated releases of turtles. Some may be unwanted pets and some are purportedly released ceremonially in association with weddings and other important events, a practice that, in certain east Asian cultures, is thought to bring good fortune.

That's the lore that forms my meager foundation of knowledge about sliders. Perhaps others can set me straight.

Kelly McAllister
Olympia, Washington
----- Original Message -----
From: MaryFrances Mathis
To: 'Tweeters'
Sent: Wednesday, August 20, 2008 8:31 PM
Subject: [Tweeters] Juanita Bay dead turtles


Tweets,

In the last few days we have discovered at least 10 dead Red-eared Sliders at Juanita Bay Park. There have been only a couple of live turtles seen during this time, as opposed to the usual dozens. We've collected a couple, and the Parks Department is going to investigate.

Has anyone seen any dead turtles anywhere else on Lake Washington? Any theories or ideas on the cause?

Comments or observations would be appreciated.

MaryFrances Mathis

Kirkland

mf.mathis at verizon.net





MaryFrances





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