Temporal and Spatial Variation of Early Mortality Syndrome in Salmonids from Lakes Michigan and Huron

Abstract

To assess the extent that early mortality syndrome (EMS) impacts different Pacific salmonid stocks and the association of EMS with thiamine, we collected eggs of coho salmon Oncorhynchus kisutch from three Lake Michigan tributaries (Platte River, Thompson Creek, and Root River) in 1996-2001. We also obtained eggs of Chinook salmon O. tshawytscha from Lake Michigan (Little Manistee River) and Lake Huron (Swan River) in 1998-2001. Unfertilized eggs from individual females were frozen for thiamine analysis, and the remainder were fertilized and reared until first feeding. We observed a high incidence of EMS in offspring when total egg thiamine levels were less than 1.7 nmol/g in both coho and Chinook salmon. In Lake Michigan strain coho salmon from the Platte River, EMS occurred in more than 70% of monitored families in 1996, 1999, 2000, and 2001, while 1997 and 1998 were years when EMS was low (Ͻ25%). Hinchenbrooke strain coho salmon from Thompson Creek exhibited greater impacts from EMS in the years when EMS was low in the Lake Michigan strain coho salmon from the Platte River. Similar to coho salmon, Lake Michigan Chinook salmon also exhibited EMS (Ͼ70%) in 1999, 2000, and 2001. Chinook salmon from Lake Huron exhibited high (Ͼ70%) EMS in 2001, moderate (40-60%) EMS in 1999, and low (Ͻ25%) EMS in 1998. Our data suggest that the incidence of EMS in salmonids varies by species, location, and year. The data support the general contention that EMS in salmonids is associated with low egg thiamine content.

Landlocked Fall Chinook Salmon Maternal Liver and Egg Thiamine Levels in Relation to Reproductive Characteristics

“…These relatively low levels may not be lethal, but lower thiamine levels can impact adult fish neurological function [19,45], metabolic rates [15,28], and muscle weakness [34], thereby potentially decreasing foraging efficiency and subsequently contributing to smaller body sizes [22,28]. Similar to that reported by other authors [14,17,30,46], free thiamine was the most prevalent form of thiamine in Lake Oahe Chinook Salmon eggs. Free thiamine likely acts as a storage vitamer and is converted to TPP or TMP later during development [46].…”

“…Overall, thiamine levels in Chinook Salmon eggs from Lake Oahe are far greater than levels found in the Great Lakes or the Baltic Sea, where thiamine deficiency complex is frequently observed. The minimum total egg thiamine level observed in this study is typical of Chinook Salmon eggs that did not exhibit thiamine deficiency complex from Lakes Michigan and Huron [30]. In Lake Michigan, Lake Huron, and Lake Ontario, mean egg total thiamine levels for Salmonids have been reported as 2.0, 3.1, and 1.3 nmol/g, respectively [32].…”

Thiamine concentrations in lake whitefish eggs from the upper Great Lakes are related to maternal diet

“…Thiamine thresholds for direct mortality vary among fish species, with estimates of egg thiamine thresholds for lake trout, Chinook salmon Oncorhynchus tshawytscha, coho salmon Oncorhynchus kisutch and Atlantic salmon Salmo salar ranging from 0.41 to 2.99 nmol·g −1 (Fisher et al, 1996;Honeyfield et al, 2005;Wolgamood et al, 2005;Werner et al, 2006;Fitzsimons et al, 2007). Rainbow smelt Osmerus mordax larvae hatched from eggs with a mean thiamine content of 2.7 nmol·g −1 showed signs of TDC (Chalupnicki et al, 2010), and walleye embryos from the Maumee River (Lake Erie) showed reduced survival below egg thiamine concentrations of approximately 6 nmol·g −1 (Rinchard et al, 2011).…”

Influence of Diet of Double-Crested Cormorants on Thiamine, Lead, and Mineral Contents of Their Eggs

“…The alewife was found to be one of the most abundant species in the diet of cormorants (Johnson et al 2002). The alewife contains the enzyme thiaminase, which destroys thiamine (vitamin B,, NRC 1983;Ji and Adelman 1998;Fitzsimons et al 2005). Consumption of alewives impairs reproduction in lake trout (Salvelinus namcrycush), coho salmon (Oncorhynchus kisutch), Chinook salmon (Oncorhynchus tshauytscha), rainbow trout (steelhead, Oncorhynchus mykiss), and brown trout (Salmo trutta) (Wolgamood et al 2005;Brown et al 2005;Fitzsimons et al 1999,2005a, 2005b, and 2007, Honeyfield et a1.1998, Homung et al 1998, Brown et al 1998,2005, Marcquenski 1996.…”

“…The alewife contains the enzyme thiaminase, which destroys thiamine (vitamin B,, NRC 1983;Ji and Adelman 1998;Fitzsimons et al 2005). Consumption of alewives impairs reproduction in lake trout (Salvelinus namcrycush), coho salmon (Oncorhynchus kisutch), Chinook salmon (Oncorhynchus tshauytscha), rainbow trout (steelhead, Oncorhynchus mykiss), and brown trout (Salmo trutta) (Wolgamood et al 2005;Brown et al 2005;Fitzsimons et al 1999,2005a, 2005b, and 2007, Honeyfield et a1.1998, Homung et al 1998, Brown et al 1998,2005, Marcquenski 1996. When nestling wood storks (Mycleria americana) were fed almost exclusively gizzard shad (Dorosoma cepedianum), a high-thiaminase fish species they developed thiamine deficiency signs including anorexia, weakness and un-coordination, all of which were reversed by vitamin supplementation (Kahl 1962, Miller 1960.…”