Fish Habitat: Essential Fish Habitat and Rehabilitation

1999 ◽  
Keyword(s):  
Life History ◽  
Water Temperature ◽  
Fish Habitat ◽  
Essential Fish Habitat ◽  
Summer Flounder ◽  
Growth And Survival ◽  
Larvae And Juveniles ◽  
Cape Hatteras ◽  
Nursery Habitats ◽  
Class Strength

<em>Abstract.</em> —To satisfy the essential fish habitat (EFH) mandate of the reauthorized Magnuson-Stevens Fishery Conservation and Management Act, the Mid-Atlantic Fishery Management Council (MAFMC) and the National Marine Fisheries Service (NMFS) are developing objective, generic criteria to describe and identify the essential habitats for their managed species. Summer flounder or fluke <em>Paralichthys dentatus </em> is an important commercial and recreational species that occurs from shallow estuaries to the outer continental shelf from Nova Scotia to Florida. It is most abundant within the Middle Atlantic Bight from New England to Cape Hatteras, and this region is the focus of this paper. Summer flounder make seasonal inshore–offshore migrations; adults and juveniles normally inhabit shallow coastal and estuarine waters during the warmer months of the year and mostly move offshore with declining water temperature and day length during autumn. Adults spawn during the fall and winter migrations. The best habitat information available on summer flounder is for the estuarinedependent transforming larvae and juveniles. They use several different estuarine habitats as nursery areas, including salt-marsh creeks, sea grass beds, mudflats, and open bay areas. In these habitats, water temperature affects the seasonal occurrence of summer flounder, drives the inshore–offshore migration, and, particularly during winter and spring, affects first-year growth and survival and thus subsequent year-class strength. The distribution of transforming larvae and juveniles within the estuaries is significantly influenced by salinity gradients and substrate. Transforming larvae and juveniles show a preference for sandy substrates in the laboratory but also have been captured on mud or mixed substrates. Juveniles are attracted to eelgrass and macroalgae habitats because of the presence of prey but remain in nearby sand to avoid predators as well as conceal themselves from the prey. The MAFMC used the life history and habitat parameter information developed by the NMFS Northeast Fisheries Science Center (NEFSC) to precisely describe the EFH of summer flounder by life stage. Because summer flounder are overexploited, the MAFMC wanted to be conservative in its EFH identification. Therefore, 90% of the areas where each life history stage has been collected from offshore surveys were identified as EFH. The MAFMC proposed that 100% of the estuaries where larvae and juveniles were identified as being present be identified as EFH because these life stages are estuarine dependent. Nursery habitats within the estuaries are essential because they provide the best conditions for growth and survival of the transforming larvae and juveniles. Submerged aquatic vegetation beds are especially vulnerable and were identified as habitat areas of particular concern. As more habitatrelated density data become available from various local, state, and federal fishery-independent surveys, updated maps of distribution and abundance will be produced.

Paddlefish Management, Propagation, and Conservation in the 21st Century

2009 ◽  
Keyword(s):  
Life History ◽  
Water Temperature ◽  
Early Life ◽  
Habitat Preferences ◽  
Early Life History ◽  
Analysis Of Covariance ◽  
Growth And Survival ◽  
Factors Affecting ◽  
River Stage ◽  
Catch Rates

<em>Abstract</em>.—How paddlefish <em>Polyodon spathula </em>early-life history dynamics affect recruitment is relatively unknown. We quantified factors affecting age-0 paddlefish abundance, hatch time, growth, and survival in an unimpounded reach of the Mississippi River during 2000–2008. We trawled several habitats, collecting 2,074 age-0 paddlefish from 10 to 170 mm total length. Paddlefish hatch timing varied across years (30–60 d), generally commencing in the middle of April and ending in June when a threshold water temperature was reached and river stage variability increased. Correspondingly, an analysis of covariance revealed a strong interaction between year and habitat for catch per unit effort in the small (10–50 mm) (<em>P </em>= 0.025) and medium (51–100 mm) (<em>P </em>= 0.040) size-classes, indicating that habitat preferences were likely influenced by year. However, no relations between these variables in the large size-class (>100 mm) existed (<em>P </em>= 0.88). Age-0 paddlefish growth rates differed among years (i.e., 1.87–3.31 mm/d) and were positively related to water temperature (<em>r </em>= 0.64; <em>P </em>= 0.083). Mortality rates varied by year (range = –0.26 to –0.57) and were positively correlated with the number of days water temperature was below 28°C during April 15 through July 15 (<em>r </em>= 0.67, <em>P </em>= 0.070). Water temperature and river stage variability may regulate early-life dynamics of paddlefish. Early-life history dynamics are likely interrelated with habitat conditions present in the river. The highest catch rates of young paddlefish were on the main channel side and side channel of islands, suggesting that these habitats are important to paddlefish. Within these habitats, paddlefish frequently occupied moderate velocities (i.e., 0.4–0.6 m/s), moderate depths (i.e., 3–5 m), and sand substrate.

scholarly journals The Value of Applying Commercial Fishers' Experience to Designed Surveys for Identifying Characteristics of Essential Fish Habitat for Adult Summer Flounder

2008 ◽  
Vol 28 (3) ◽  
pp. 710-721 ◽  
Author(s):  
H. Ward Slacum ◽  
Jon H. Vølstad ◽  
Edward D. Weber ◽  
William A. Richkus ◽  
Robert J. Diaz ◽  
...  
Keyword(s):  
Fish Habitat ◽  
Essential Fish Habitat ◽  
Summer Flounder

scholarly journals Life histories and distribution of ostracods with depth in western Lake Geneva (Petit-Lac), Switzerland: a reconnaissance study

Crustaceana ◽  
2014 ◽  
Vol 87 (8-9) ◽  
pp. 1095-1123 ◽  
Author(s):  
Laurent Decrouy ◽  
Torsten W. Vennemann
Keyword(s):  
Life History ◽  
Water Temperature ◽  
Water Depth ◽  
Organic Matter Content ◽  
Environmental Parameters ◽  
Late Winter ◽  
Lake Geneva ◽  
Monthly Basis ◽  
Sampling Campaign ◽  
Western Lake

Because environmental conditions within a given basin are different for each season and at different water depth, knowledge of the life history and depth distribution of target species is important for environmental and palaeoenvironmental interpretations based on ostracod species assemblages and/or the geochemical compositions of their valves. In order to determine the distribution of species with depth as well as the life history of species from Lake Geneva, a one-year sampling campaign of living ostracods was conducted at five sites (2, 5, 13, 33 and 70 m water depth) on a monthly basis in the Petit-Lac (western basin of Lake Geneva, Switzerland). Based on the results, the different species can be classified into three groups. Littoral taxa are found at 2 and 5 m water depth and include, in decreasing numbers of individuals,Cypridopsis vidua(O. F. Müller, 1776),Pseudocandona compressa(Koch, 1838),Limnocythere inopinata(Baird, 1843),Herpetocypris reptans(Baird, 1835),Potamocypris smaragdina(Vávra, 1891),Potamocypris similis(G. W. Müller, 1912),Plesiocypridopsis newtoni(Brady & Robertson, 1870),Prionocypris zenkeri(Chyzer & Toth, 1858) andIlyocyprissp. Brady & Norman, 1889. Sublittoral species are found in a majority at 13 m water depth and to a lesser extend at 33 m water depth and include, in decreasing numbers of individuals,Fabaeformiscandona caudata(Kaufmann, 1900),Limnocytherina sanctipatricii,Candona candida(O. F. Müller, 1776) andIsocypris beauchampi(Paris, 1920). Profundal species are found equally at 13, 33 and 70 m water depth and includes, in decreasing numbers of individuals,Cytherissa lacustris(Sars, 1863),Candona neglectaSars, 1887 andCypria lacustrisLilljeborg, 1890. The occurrence ofLimnocytherina sanctipatricii(Brady & Robertson, 1869) is restricted from late winter to late spring when temperatures are low, whileC. vidua,L. inopinata,P. smaragdina,P. similis,P. newtoniandIlyocyprissp. occur predominantly from spring to early autumn when temperatures are high. Individuals ofC. neglecta,C. candida,F. caudata,P. compressa,C. lacustris,H. reptansandCp. lacustrisoccur throughout the year with juveniles and adults occurring during the same period (C. neglectaat 70 m,C. lacustrisat 13, 33 and 70 m, andH. reptansat 2, 5 and 13 m water depth) or with juveniles occurring during a different period of the year than adults (C. neglectaat 13 and 33 m andC. candida,F. caudataandP. compressaat their respective depth of occurrence). Among the environmental parameters investigated, an estimate of the relationship between ostracod autoecology and environmental parameters suggests that in the Petit-Lac: (i) water temperature and substrate characteristics are important factors controlling the distribution of species with depth, (ii) water temperature is also important for determining the timing of species development and, hence, its specific life history, and (iii) water oxygen and sedimentary organic matter content is less important compared to the other environmental parameter monitored.

Colonization patterns and life-history dynamics of Culex mosquitoes in artificial ponds of different character

1993 ◽  
Vol 71 (3) ◽  
pp. 568-578 ◽  
Author(s):  
D. Dudley Williams ◽  
Annette Tavares-Cromar ◽  
Donn J. Kushner ◽  
John R. Coleman
Keyword(s):  
Life History ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Larval Development ◽  
Development Time ◽  
Larval Density ◽  
Strong Relationship ◽  
Terrestrial Vegetation ◽  
Widespread Species ◽  
Artificial Ponds

The relationship between the biology and habitat of larval mosquitoes was studied in a series of artificial ponds of differing characteristics established across a terrestrial vegetation gradient from open fields to deep woods. The ponds were uniformly colonized by two widespread species of Culex, both characteristic of small bodies of water, including artificial, "container" habitats. First-instar larvae of Culex restuans were found within 2 days of filling the ponds with water and four or five generations were produced from May until the end of September. One very long generation occurred in July, which corresponded to maximum larval densities. Overall, there was a strong relationship between larval development time of C. restuans and larval density. A few larvae of Culex pipiens pipiens occurred sporadically throughout the summer, but numbers did not increase until C. restuans populations began to wane in late July. Thereafter two, or possibly three, generations were produced into the autumn. The patterns of colonization, synchrony of life history, and growth of these two species were remarkably consistent amongst the ponds, despite considerable variation in both their physical and biological environments (e.g., over the 2 years of study, conductivity ranged from 20 to 890 μS, pH from 6.4 to 10.7, dissolved oxygen from 0 to 13.5 ppm, and water temperature from 5 to 29.8 °C). Density of C. restuans was related to water temperature and pH at the "open" site and to water temperature, dissolved oxygen, percent algae, and percent detritus at the "edge of the woods" site. At the "deep woods" site, larval numbers were related to temperature, pH, conductivity, and dissolved oxygen. At both the edge and deep wood sites, larval development time of C. restuans increased with mean water temperature to 20 °C. Above this temperature, larval development time tended to decrease.

Observations on Phaeosaccion collinsii in culture

1971 ◽  
Vol 49 (4) ◽  
pp. 563-566 ◽  
Author(s):  
J. McLachlan ◽  
L. C.-M. Chen ◽  
T. Edelstein ◽  
J. S. Craigie
Keyword(s):  
Life History ◽  
Nova Scotia ◽  
Water Temperature ◽  
Spore Germination ◽  
Light Intensities ◽  
History Of ◽  
Single Locality

The life history of Phaeosaccion collinsii Farlow, a species which is known from a single locality in Nova Scotia, has been completed in culture. There was no indication of a sexual phase and zoospores gave rise directly to the tubular thallus. Completion of the life history occurred at 5 °C only. At higher temperatures spores failed to germinate, or growth and differentiation were suppressed. Light intensities exceeding 100 ft-c inhibited spore germination, although growth and differentiation were not similarly affected. In nature mature plants occur sublittorally, and are present only in spring when the water temperature is around 5 °C. Zoospore flagellation is of the typical heterokont type with the flimmer bearing bilateral hairs. On this basis P. collinsii can be placed either in the Chrysophyceae or Phaeophyceae.

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