Freshwater to Seawater Transitions in Migratory Fishes

Zydlewski, Joseph D.; Wilkie, Michael P.

doi:10.1016/b978-0-12-396951-4.00006-2

Cited by 48 publications

(33 citation statements)

References 429 publications

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“…This result establishes a critical link between the physiological preparation of smolts in freshwater for osmoregulation in the ocean and survival, which has been long suspected by others (Boeuf 1993;Itokazu et al 2014). A rich literature exists describing the physiological transformations of diadromous fishes (e.g., Zydlewski and Wilkie 2013), and the study of smolt physiology constitutes a large body of work within that field McCormick 2013). It is well established that gill NKA activity is a useful indicator of osmoregulatory ability (Zaugg and McLain 1972;McCormick et al 1998McCormick et al , 2009) and migratory readiness in salmonids (Aarestrup et al 2000).…”

Section: Modelmentioning

confidence: 62%

Linking Behavior, Physiology, and Survival of Atlantic Salmon Smolts During Estuary Migration

et al. 2015

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Decreased marine survival is identified as a component driver of continued declines of Atlantic Salmon Salmo salar. However, estimates of marine mortality often incorporate loss incurred during estuary migration that may be mechanistically distinct from factors affecting marine mortality. We examined movements and survival of 941 smolts (141 wild and 800 hatchery‐reared fish) released in freshwater during passage through the Penobscot River estuary, Maine, from 2005 to 2013. We related trends in estuary arrival date, movement rate, and survival to fish characteristics, migratory history, and environmental conditions in the estuary. Fish that experienced the warmest thermal history arrived in the estuary 8 d earlier than those experiencing the coolest thermal history during development. Estuary arrival date was 10 d later for fish experiencing high flow than for fish experiencing low flow. Fish released furthest upstream arrived in the estuary 3 d later than those stocked further downstream but moved 0.5 km/h faster through the estuary. Temporally, movement rate and survival in the estuary both peaked in mid‐May. Spatially, movement rate and survival both decreased from freshwater to the ocean. Wild smolts arrived in the estuary later than hatchery fish, but we observed no change in movement rate or survival attributable to rearing history. Fish with the highest gill Na+, K+‐ATPase activity incurred 25% lower mortality through the estuary than fish with the lowest gill Na+, K+‐ATPase activity. Smolt survival decreased (by up to 40%) with the increasing number of dams passed (ranging from two to nine) during freshwater migration. These results underscore the importance of physiological preparedness on performance and the delayed, indirect effects of dams on survival of Atlantic Salmon smolts during estuary migration, ultimately affecting marine survival estimates. Received October 25, 2014; accepted January 8, 2015

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Section: Modelmentioning

confidence: 62%

Linking Behavior, Physiology, and Survival of Atlantic Salmon Smolts During Estuary Migration

et al. 2015

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“…As the primary aim of this review is to assess the reasons for the apparent lack of colonization of estuaries by freshwater fish species from the catchment in comparison with marine species from the sea, diadromous and estuarine resident taxa (Potter et al, in press) have not been the focus of attention. It is accepted that catadromous, anadromous, amphidromous and estuarine-resident species are all euryhaline, with members of the diadromous group switching their osmoregulatory mechanisms as they pass from fresh water to the sea or vice versa (Zydlewski & Wilkie, 2012). Panikkar (1960) was one of the early authors who suggested that the most essential adaptation required by fishes to enter estuaries is an ability to adjust to changing salinity regimes.…”

Section: Introductionmentioning

confidence: 99%

Why are there so few freshwater fish species in most estuaries?

Whitfield

2015

Journal of Fish Biology

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The freshwater fish assemblage in most estuaries is not as species rich as the marine assemblage in the same systems. Coupled with this differential richness is an apparent inability by most freshwater fish species to penetrate estuarine zones that are mesohaline (salinity: 5·0-17·9), polyhaline (salinity: 18·0-29·9) or euhaline (salinity: 30·0-39·9). The reason why mesohaline waters are avoided by most freshwater fishes is difficult to explain from a physiological perspective as many of these species would be isosmotic within this salinity range. Perhaps, a key to the poor penetration of estuarine waters by freshwater taxa is an inability to develop chloride cells in gill filament epithelia, as well as a lack of other osmoregulatory adaptations present in euryhaline fishes. Only a few freshwater fish species, especially some of those belonging to the family Cichlidae, have become fully euryhaline and have successfully occupied a wide range of estuaries, sometimes even dominating in hyperhaline systems (salinity 40+). Indeed, this review found that there are few fish species that can be termed holohaline (i.e. capable of occupying waters with a salinity range of 0-100+) and, of these taxa, there is a disproportionally high number of freshwater species (e.g. Cyprinodon variegatus, Oreochromis mossambicus and Sarotherodon melanotheron). Factors such as increased competition for food and higher predation rates by piscivorous fishes and birds may also play an important role in the low species richness and abundance of freshwater taxa in estuaries. Added to this is the relatively low species richness of freshwater fishes in river catchments when compared with the normally higher diversity of marine fish species for potential estuarine colonization from the adjacent coastal waters. The almost complete absence of freshwater fish larvae from the estuarine ichthyoplankton further reinforces the poor representation of this guild within these systems. An explanation as to why more freshwater fish species have not become euryhaline and occupied a wide range of estuaries similar to their marine counterparts is probably due to a combination of the above described factors, with physiological restrictions pertaining to limited salinity tolerances probably playing the most important role.

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“…Van zoetwater naar zoutwater betekent een hormonaal gestuurd proces waarbij allerlei processen op gang komen zoals: veranderingen in de kieuw ionocyten (dit zijn cellen die voor een juist evenwicht tussen water en zouten in het lichaam zorgen), verhoogd zeewater opname en water opname in de darmen en verminderd vocht verlies via de urine (Zydlewski et al 2012). Zij zijn dan op zoek naar paai of opgroeigebieden.…”

Section: Figuur 6 Successiepatronen Van Zoute Brakke En Zoete Schorunclassified

Ecologie van zoet-zout overgangen in deltagebieden : literatuurstudie en beoordeling van een scenario in het Volkerak-Zoommeer

Tangelder¹,

Winter²,

Ysebaert³

2017

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Freshwater to Seawater Transitions in Migratory Fishes

Cited by 48 publications

References 429 publications

Linking Behavior, Physiology, and Survival of Atlantic Salmon Smolts During Estuary Migration

Linking Behavior, Physiology, and Survival of Atlantic Salmon Smolts During Estuary Migration

Why are there so few freshwater fish species in most estuaries?

Ecologie van zoet-zout overgangen in deltagebieden : literatuurstudie en beoordeling van een scenario in het Volkerak-Zoommeer

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