Mortality and growth of 0-group flatfish in the brackish dollard (Ems Estuary, Wadden Sea)

The effect of rising seawater temperature on growth of 0-group sole Solea solea and plaice Pleuronectes platessa in the southeastern North Sea was investigated for the period 1970 to 2004 using annual autumn pre-recruit survey data and frequent surveys on a nursery ground. Autumn length showed an increasing trend in sole but not in plaice. Increasing winter temperatures significantly increased the growing period of sole, a warm-water species that spawns in spring, but not of plaice, a temperate species that spawns in winter. Growth rate increased with higher summer temperatures in sole and to a lesser degree in plaice. Compared to experimental growth rates at ambient temperatures and unlimited food, observed growth rates were close to experimental values until mid-June but were much lower in July to September, suggesting food limitation in summer. The higher temperatures observed since 1989 positively affected the quality of the shallow coastal waters as a nursery area for sole but not for plaice. A further increase may negatively affect the nursery quality if the production rate of benthic food cannot meet the increase in energy requirements of 0-group flatfish.KEY WORDS: Climate change · Temperature · Growth · Food limitation · Juvenile · Sole · Solea solea · Plaice · Pleuronectes platessa · Spawning time · North Sea 358: 219-230, 2008 production coincided with an increased input of nitrates and phosphates in the 1960s and 1970s (Beukema & Cadée 1988, Colijn et al. 2002. It is expected that productivity in this area has decreased since the mid-1980s in response to the reduction in nutrient input (Boddeke & Hagel 1995, Lenhart 2001, but this is still under debate (Cadée & Hegeman 2002, Philippart et al. 2007). Resale or republication not permitted without written consent of the publisherMar Ecol Prog SerThe coastal waters of the southeastern North Sea are important nursery grounds for juvenile flatfish like sole Solea solea and plaice Pleuronectes platessa (Zijlstra 1972, van Beek et al. 1989. Detailed studies suggest that growth of 0-group flatfish is determined by ambient temperature conditions and not by food conditions (van der Veer & Witte 1993), as has been reported for sole (Pihl 1989, Rogers 1994, van der Veer et al. 2001, Amara 2003, plaice (Zijlstra et al. 1982, van der Veer & Witte 1993, Amara 2003 and flounder (Pihl 1989, van der Veer et al. 1991. Only a few studies provided evidence for reduced growth in plaice (Nash et al. 1994), either through intra-specific competition (Rijnsdorp & van Leeuwen 1992, Modin & Pihl 1994 or through changes in the abundance or quality of food (Berghahn et al. 1995). On a large spatial scale, however, indirect support for the role of food quality and/or quantity is provided by the observed increase in growth of juvenile plaice and sole in the 1960s and 1970s (Rijnsdorp & van Leeuwen 1992, Millner & Whiting 1996, which could be related to the eutrophication of the coastal waters and the observed increase in benthic biomass (Reise 1982, Beukema & Cadée 198...

Section: Growth Ratementioning

confidence: 73%

Section: Growth Ratementioning

confidence: 99%

Effects of climate change on growth of 0-group sole and plaice

Teal¹,

Leeuw²,

Veer³

et al. 2008

“…The results for sole are particularly indicative of how this mechanism may act: in the beginning of the growing season, the RG of sole is higher in southern compared with northern areas; however, throughout the season this pattern inverses. In contrast to northern European areas where sole only occur after plaice and flounder have settled (Jager et al 1995, Amara et al 2001, Van der Veer et al 2001a, in southern European nurseries, sole juveniles are the first marine species to colonize these areas, appearing in April−May (Cabral 2003, Dolbeth et al 2010, and in some years, young-of-the-year can even be observed from late January onwards (Martinho et al 2008). This could confer an advantage to sole by occupying an empty niche with ample food resources, which, combined with high summer temperatures, would allow for fast growth.…”

Section: Latitudinal Trendsmentioning

confidence: 99%

Latitudinal trends in habitat quality of shallow‑water flatfish nurseries

Freitas¹,

Kooijman²,

Veer³

2012

The habitat quality of European shallow-water nurseries was studied for 3 common flatfish species based on juvenile growth conditions. Field growth of 0-group plaice Pleuronectes platessa, flounder Platichthys flesus and sole Solea solea, from both published and unpublished studies, was compared with maximum growth predicted by a bioenergetics model based on the dynamic energy budget theory. In plaice and flounder, realized growth ratio decreased consistently during the growing season in most of the nurseries analyzed, indicating a widespread pattern of declining conditions. In sole, growth performance was not maximal, but as opposed to the other species, no clear temporal trend in realized growth ratio was observed. A latitudinal comparison of realized growth ratio over the various nurseries indicated clear positive trends for plaice and flounder, with better growth conditions at northern latitudes. In sole, despite some variability, the same trend was found during part of the summer. In the absence of clear gradients in benthic prey biomass, we hypothesize that increased food limitation in southern locations is most likely caused by interspecific competition reducing maximum individual intake rates. These results suggest that, in the context of global warming, habitat quality of southern European nurseries for juvenile growth may be particularly affected by the combined interaction of food and thermal constraints.

“…As a result, better understanding of processes controlling nursery-ground formation often demands simultaneous assessment of the ways in which early juvenile distributions are shaped by supply-side and post-settlement processes. Relationships between preand post-settlement processes and year-class strength in fishes and invertebrates, including mobile flatfishes, have been extensively studied (Zijlstra et al 1982, van der Veer 1986, Houde 1987, Beverton & Iles 1992, Hines & Ruiz 1995, Jager et al 1995, Nash & Geffen 2000, van der Veer et al 2000. However, studies of the combined effects of pre-and early post-settlement processes on the spatial distributions of juveniles have largely been confined to siteattached invertebrates and reef fishes (Caselle & Warner 1996, Eggleston et al 1998, Shima 2001.…”

Section: Introductionmentioning

confidence: 99%

Winter flounder settlement dynamics and the modification of settlement patterns by post-settlement processes in a NW Atlantic estuary

Manderson

Pessutti²,

Meise³

et al. 2003

For fishes with bipartite life cycles, locations of high quality nursery grounds are determined by processes controlling larval supply as well as those affecting early juvenile mortality and emigration. From April through June 2000, distributions of settling and early juvenile winter flounder Pseudopleuronectes americanus were measured to examine how pre-and post-settlement processes determine the location of the primary nursery ground in the Navesink River/Sandy Hook Bay estuarine system (NSBES), New Jersey. The settlement pattern, measured with fine mesh (3 mm) traps that captured flounder ≤ 8 d into the post-metamorphic age but excluded predators and prevented emigration, was spatially dynamic. Fish settled on organically rich substrata (organic content = 5 to 12% by weight) 2 wk earlier in the Navesink River (mid-April through mid-May) than on similar substrata just 15 km downstream in Sandy Hook Bay (May through mid-June). Local retention mechanisms combined with spatial variation in spring warming, which probably affected larval-stage durations, appeared to be responsible for the dynamic settlement pattern. To determine whether spatial patterns of flounder settlement were dramatically altered by post-settlement processes, we compared settler supply (measured using traps) with juvenile distributions (measured using beam trawls, which do not prevent post-settlement mortality and emigration). The index of settler supply explained 95% of the variation in juvenile abundance patterns in the Navesink River (p < 0.001) where larger juveniles > 20 mm standard length were commonly trawled. However, larger juveniles were nearly absent in Sandy Hook Bay, where juvenile distributions were not related to settlement (r 2 = 0.15, p = 0.31). Thus, the upstream distribution of juvenile winter flounder in the NSBES, which is similar to that observed in other estuarine nurseries, appeared to be produced by the rapid modification of settlement patterns by post-settlement processes. However, pre-settlement processes that produce spatial variation in the timing of settlement could affect the ways in which settlement patterns are modified by age, time and/or size dependent post-settlement processes.KEY WORDS: Dynamic habitat · Nursery · Supply side processes · Post-settlement processesResale or republication not permitted without written consent of the publisher