The Role of American White Pelicans in the Life 

 Cycle and Spread of the Bolbophorus Catfish 

 Trematode — The bolbophorus catfish trematode 

 (Bolbophorus damnlficus) is associated with 

 high mortality rates in catfish fingerlings and the 

 formation of cysts in the fillets of mature catfish. 

 NWRC scientists collaborated with parasitologists 

 from the Mississippi State University College of 

 Veterinary Medicine to determine the role American 

 white pelicans play in the life cycle and spread of B. 

 damniflcus in catfish. NWRC scientists confirmed 

 the life cycle of this trematode and compared 

 it to the known life cycle of a similar species. 

 The research provided further evidence that B. 

 damnificus is a distinct species and the causative 

 agent for trematode-associated deaths in catfish. 

 The research also showed that the American white 

 pelican is the definitive avian host. 



NWRC biologists are investigating winether tine American wtnite 

 peiican can spread wtnirling disease among rivers, lakes, and 

 ponds. 



Additional studies were conducted to identify other 

 potential intermediate hosts for the infectious 

 trematode. Results confirmed that the Planorbella 

 trivolvis (a freshwater snail) population native to the 

 Mississippi Delta is a first intermediate host for B. 

 damnificus. The studies also demonstrated that the 

 P. trivolvis population found in North Dakota may 

 also serve as intermediate hosts. Populations of 

 these snails are present in both the breeding and 

 wintering ranges of the American white pelican and 

 are susceptible to B. damnificus infection, which 

 may serve to perpetuate the B. damnificus life cycle 

 in the North-Central United States. 



Cormorant Movement Patterns Identified — NWRC 

 scientists attached satellite telemetry transmitters 

 to DCCOs captured at roosts near aquaculture 

 facilities in Alabama, Arkansas, Louisiana, and 

 Mississippi to develop a better understanding of 

 the winter and summer movements of cormorants 

 using aquaculture farms in the Southeastern United 

 States. The winter home ranges for all cormorants 

 averaged 37,384 km% with 3,467 km^ in the core 

 use area. In summer, cormorants occupy a smaller 

 territory — 29,300 km" on average — and 2,889 km^ 

 in the core use area. There were no differences in 

 the ranges of adult v immature birds or between 

 capture regions (e.g., the Mississippi River flood 

 plain of Arkansas, Louisiana, and Mississippi or 

 eastern Mississippi and western Alabama). 



This study verified that cormorants using 

 aquaculture facilities in the Southeast are from the 

 same population as those that are thought to impact 

 natural resources in the Great Lakes region. Data 

 from this study may be used to provide information 

 necessary for regional and/or flyway-based DCCO 

 population management strategies. 



Biologists attach satellite transmitters to DCCOs to study their 

 migration patterns and response to management activities. 



5 Developing Methods 



