Challenges for Diadromous Fishes in a Dynamic Global Environment

Poster Sessions Preamble

John E. Cooper

doi: https://doi.org/10.47886/9781934874080.ch53

Diadromy encompasses a wide range of life history characteristics, many of which are altered during the life cycle of the organism. Research is often focused into many narrow topics, but understanding the interactions between the environment and the organism requires a broad approach that incorporates the topics into a cohesive whole. It is hoped that this can be facilitated with the presentations of the following abstracts. The authors present new ideas on physiology, genetics, migration (in relation to ocean currents, barriers, pollutants, parasites, and diseases), growth in ocean and freshwater environments, behavior, design of fishways, analysis of stream networks, forming partnerships for stock restoration, and policy needs.

The underlying theme of these presentations (either expressed or implied) is the physical and chemical characteristics of habitat and how well we understand the responses of organisms to the unstable nature of the habitat caused by human activity. The organisms evolved with specific, or at least preferred, needs in habitat and must now adapt to altered conditions caused by migratory barriers, sedimentation, introduced chemical pollutants, and climate change. The effects of barriers, loss of historic substrate, introduced chemicals that can mask natural migratory cues, and changes in the open ocean are examined in the abstracts presented here, as well as possible solutions to some of these problems. However, the changes to specific habitats may be occurring faster than the pace of our understanding of what is needed for each species.

Advancements in technology have vastly improved our ability to collect fine-scale data that reveals migration movements and duration, growth habitats, and interactions of predator and prey, but can we utilize these tools quickly enough to restore the declining populations of organisms?

The primary authors represent nine countries and present information on more than 17 fish species: eels and salmonids were the more numerous, as in American Fisheries Society Symposium 1, Common Strategies of Anadromous and Catadromous Fishes, in 1986, but galaxids, ayu Plecoglossus altivelis, coregonids, smelt, lampreys, shads, sturgeons, and striped bass Morone saxatilis were also discussed. The presentation on diadromous invertebrates reminds us that diadromy is not limited to fish.

The 62 abstracts submitted for the meeting in Halifax required two separate sessions and were presented as they related to the paper sessions. Authors were given the choice of preparing extended abstracts for this publication, and these 24 abstracts, as well as 33 short abstracts, are presented here in the order of the respective paper session.