Selective Tidal Stream Transport of Flounder Larvae (Platichthys flesusL.) in the Dollard (Ems Estuary)

Mechanisms promoting upriver transport of larvae of two fish species in the Hudson River estuary

“…Weinstein et al 1980, Forward et al 1999, Grioche et al 2000, while in other species movements were solely synchronized to the M2 tide (e.g. Fortier & Leggett 1983, Rowe & Epifanio 1994, Jager 1999 or to the day/night cycle (Fortier & Leggett 1983). Diel migration of the kind we have observed, with movement into the water column during night flood tides and down towards the bottom at other times, can promote upriver transport (Hill 1991).…”

“…Previous work has focused on larval depth distribution; because estuarine flow has relatively high vertical shear, along-estuary advection will be sensitive to vertical position. Up-estuary transport is promoted by larval preference for deeper water, possibly in combination with a migration into shallower waters during flood tides (referred to as selective tidal stream transport: reviews by Shaw 1984 andBoehlert &Mundy 1988; recent findings include those of Rowe & Epifanio 1994, Yamashita et al 1996, Forward et al 1999, Jager 1999, Welch et al 1999, and Grioche et al 2000. Diel vertical migration can also influence advection (Hill 1991).…”

Plasticity of European flounder life history patterns discloses alternatives to catadromy

“…River plumes can also be suitable habitats for pre-metamorphic and metamorphic larvae, similarly to estuarine nurseries, because they also provide enough food for larvae to sustain enhanced growth rates (De Vries et al 1990). Those larvae and juveniles that have not made direct settlement and/or rapid settlement into an estuarine nursery could use selective tidal stream transport to migrate upstream into an estuary (Bos 1999, Jager 1999. The intricate relationship between otolith microchemistry, river plume and habitat use/natal origin suggests that further studies are required.…”

“…However, there is still controversy about classifying flounder as catadromic, semi-catadromic, estuarine migrant, marine-estuarine opportunistic (Elliott et al 2007) or even as a truly estuarine resident species (Elliott & Dewailly 1995). Recent works clearly proved that flounder is not an estuarine resident species (Daverat et al 2011, Morais et al 2011, although field observations confirmed that flounder use estuarine habitats (Jager 1999, Marchand et al 2003 as well as freshwater habitats for extended periods (Radforth 1940, Beaumont & Mann 1984. Indeed, freshwater was found to trigger the metamorphosis of flounder (Hutchinson & Hawkins 2004), and larvae are able to migrate upstream efficiently to their estuarine nursery ground using selective tidal transport (Bos 1999).…”

Chronobiology: implications for marine resource exploitation and management

“…This behaviour was shown to retain the larvae near the adult oyster beds within the estuary. More recent observations have also been made on a number of other commercial molluscs, crustaceans and fish in estuaries, which achieve retention or recruitment of dispersed larvae, juveniles or adults back into estuaries by the process of selective tidal-stream transport (Jager, 1999;Forward and Tankersley, 2001;Gibson 2003). Similar observations have also been made on species in inshore coastal seas where tidal streams are strong, with clear evidence emerging in several species of endogenous clock control of tidal rhythms of dispersal and recruitment behaviour (Zeng and Naylor, 1996a,b;Forward and Tankersley, 2001;Gibson, 2003).…”