Temporal variation in winter flounder recruitment at the southern margin of their range: is the decline due to increasing temperatures?

Abstract

The southern-most stock of winter flounder (Pseudopleuronectes americanus), a cold temperate species of the Northwest Atlantic, has not recovered from overfishing despite continued restrictive measures, and appears to be contracting northward. We regressed larval and settled juvenile abundance (after accounting for adult and larval contribution to variation, respectively) on temperature over several decades from collections in New Jersey, the United States, at the southern edge of their range to determine if increasing temperatures during the first year of life were responsible for this contraction. A significant stock–recruitment relationship at both stages was moderate, explaining 27.5% of the variance for larvae on adults and 20.6% for juveniles on larvae. There was no significant effect of average monthly temperature in explaining variance of the residuals for larvae, or of degree day on explaining the abundance of residuals for juveniles over a months-long settlement period. However, in both cases, residuals were widely distributed at cold temperatures, while they were always low at warm temperatures. Thus, years in which spring temperatures were warm (5–7oC for February, 7–9 for March, and 11–20 for May) always experienced poor recruitment. This threshold effect may result from an intersection with predators in response to temperature, and this may play a more important role than heat stress in determining recruitment success.

Environmentally driven forecasts of northern rock sole (Lepidopsetta polyxystra) recruitment in the eastern Bering Sea

“…A cold pool threshold is consistent with the idea that environment-recruitment effects can be non-linear (Ciannelli, Chan, Baily, & Stenseth, 2004). A similar, but reversed temperaturerecruitment threshold pattern is hypothesized for American flounder at the equatorial edge of their range, where poor recruitment always occurs during warm years (Able et al, 2014). The form of the cold pool index and recruitment relationship is important because model form mis-specification decreases the predictive capabilities of recruitment models (De Oliveira & Butterworth, 2005), and this relationship should be re-examined in the future when more data are available to evaluate the hypothesized threshold effect and possibly refine the threshold value.…”

Trophic structure of a coastal fish community determined with diet and stable isotope analyses

“…While the decline in P . americanus is not attributed to increased competition for resources, it is important to consider competitive interactions when designing fishery management plans (Nye et al , ; Link & Auster, ; Able et al , ). Similarly, the functional overlap between C .…”

Windowpane flounder (Scophthalmus aquosus) and winter flounder (Pseudopleuronectes americanus) responses to cold temperature extremes in a Northwest Atlantic estuary

“…Windowpane and winter flounder distributions overlap throughout the Northwest Atlantic, with windowpane more abundant to the south (near Chesapeake Bay) and winter flounder more abundant at higher latitudes (north of Cape Cod; Collette and Klein-MacPhee, 2002). Temperature may determine the range and local abundances of windowpane at its northern limit (Chang et al, 1999) and winter flounder at its southern limit (Able et al, 2014;Bell et al, 2014). These species differ in their physiological adaptations to thermal stress as well as seasonal patterns of reproduction; therefore individuals of each species enter their first winter at different ages and sizes and have different susceptibilities to cold temperature stress (Table 1).…”

“…For instance, warmer temperatures may increase thermal stress for some species at the southern extent of their ranges (Desaunay et al, 2006;Rijnsdorp et al, 2009). Fish distributions may shift toward higher latitudes, reflecting either a range expansion into areas that historically were too cold (Stebbing et al, 2002) or an emigration from areas no longer cold enough (Able et al, 2014). Warmer temperatures also may increase larval mortality on a regional scale, which synchronizes interannual variation in recruitment for subpopulations and destabilizes resilience to disturbances for regional stocks (Manderson, 2008;Bell et al, 2014).…”

“…Winter flounder (Pseudopleuronectes americanus) supports important commercial and recreational fisheries in the region that have declined substantially for inshore populations (ASMFC, Atlantic States Marine Fisheries Commission, 2006) in part, because of overfishing in the 1980s and poor recruitment in the late 1990s and 2000s (Able et al, 2014). Winter flounder are demersal throughout their life cycle and therefore are particularly susceptible to impacts to benthic habitat, such as dredging which is needed to maintain and deepen navigation channels for port operations in the Harbor.…”