A pilot study of hogfish (Lachnolaimus maximus Walbaum 1792) movement in the Conch Reef Research Only Area (northern Florida Keys)

The largely sedentary behavior of many fishes on coral reefs is well established. Information on the movement behavior of individual fish, over fine temporal and spatial scales, however, continues to be limited. It is precisely this type of information that is critical for evaluating the success of marine reserves designed for the conservation and/or management of vagile fishes. In this pilot study we surgically-tagged eight hogfish (Lachnolaimus maximus Walbaum 1792) with coded-acoustic transmitters inside the Conch Reef Research Only Area (a no-take marine reserve) in the northern Florida Keys National Marine Sanctuary. Our primary objective was to characterize the movement of L. maximus across Conch Reef in the vicinity of the reserve. All fish were captured, surgically-tagged and released in situ during a saturation mission to the Aquarius Undersea Laboratory, which is located in the center of the reserve. Movement of tagged L. maximus was recorded for up to 95 days by three acoustic receivers deployed on the seafloor. Results showed clear diel patterns in L. maximus activity and regular movement among the receivers was recorded for seven of the eight tagged fish. Fidelity of tagged fish to the area of release was high when calculated at the scale of days, while within-day fidelity was comparatively low when calculated at the scale of hours. While the number of fish departures from the array also varied, the majority of departures for seven of the eight fish did not exceed 1-hr (with the exception of one 47-day departure), suggesting that when departures occurred, the fish did not travel far. Future efforts will significantly expand the number of receivers at Conch Reef such that fish movement behavior relative to the reserve boundaries can be quantified with increased temporal and spatial resolution. (PDF contains 22 pages.)

Synopsis of biological data on the Nassau grouper, Epinephelus striatus (Bloch, 1792), and the jewfish, E. itajara (Lichenstein, 1822)

Information on the biology, fishery resources, explotiation patterns, management, and conservation status of two species of grouper-the Nassau grouper, Epinephelus striatus, and the jewfish, Epinephelus itajara-is compiled, reviewed, and analyzed. (PDF file contains 68 pages.)

Biology and assessment of the painted sweetlips (Diagramma pictum (Thunberg, 1792)) and the spangled emperor (Lethrinus nebulosus (Forsskål, 1775)) in the southern Arabian Gulf

The population biology and status of the painted sweeplips (Diagramma pictum) and spangled emperor (Lethrinus nebulosus) in the southern Arabian Gulf were established by using a combination of size-frequency, biological, and size-at-age data. Transverse sections of sagittal otoliths were characterized by alternating translucent and opaque bands that were validated as annuli. Comparisons of growth characteristics showed that there were no significant differences (P>0.05) between sexes. There were well defined peaks in the reproductive cycle, spawning occurred from April to May for both species, and the mean size at which females attained sexual maturity was 31.8 cm fork length (LF) for D. pictum and 27.6 cm (LF) for L. nebulosus. The mean sizes at first capture (21.1 cm LF for D. pictum and 26.4 cm LF for L. nebulosus) were smaller than the sizes for both at first sexual maturity and those at which yield per recruit would be maximized. The range of fishing-induced mortality rates for D. pictum (0.37−0.62/yr) was substantially greater than the target (Fopt=0.07/yr) and limit (Flimit=0.09/ yr) estimates. The range of fishing-induced mortality rates for L. nebulosus (0.15/yr to 0.57/yr) was also in excess of biological reference points (Fopt=0.10/yr and Flimit=0.13/yr). In addition to growth overfishing, the stocks were considered to be recruitment overfished because the biomass per recruit was less than 20% of the unexploited levels for both species. The results of the study are important to fisheries management authorities in the region because they indicate that both a reduction in fishing effort and mesh-size regulations are required for the demersal trap fishery.

A preliminary study on the feeding regime of European pilchard (Sardina pilchardus Walbaum 1792) in Izmir Bay, Turkey, Eastern Aegean Sea

The gut contents of Sardina pilchardus specimens captured in Izmir Bay were examined in order to determine their feeding regimes. Of the 365 stomachs examined, 321 (87.95%) contained food and 44 (12.05%) were empty. Analysis of gut contents verified that S. pilchardus feeds on zooplankton. The most important group in the diet of S. pilchardus was copepods (79.79%). Decapod crustacean larvae (8.17%) and bivalves (3.18%) were second and third, respectively, in order of importance. The application of analysis of variance to monthly data of numerical percentage, weight percentage, frequency of occurrence and index of relative importance indicated that there was no significant difference between months. Oncaea media was the most dominant species for six months of the year. Euterpina acutifrons, Centropages typicus, Calanoida, Oncaea sp. and Corycaeus sp. were the most dominant for March, April, May, September, October and December.

Optimum dietary carbohydrate to lipid ratio in stinging catfish, Heteropneustes fossilis (Bloch, 1792)

A feeding trial of 8 weeks was conducted in a static indoor rearing system to investigate the optimum carbohydrate to lipid ratio (CHO:L ratio) in stinging catfish, Heteropneustes fossilis. Five iso-nitrogenous (35% crude protein) and iso-energetic (17.06 kJ gˉ¹ gross energy (GE)) fish meal based diets with varying carbohydrate to lipid (CHO:L g/g) ratios of 0.60, 0.98, 1.53, 2.29 and 3.44 for diets 1-5, were tested, respectively. The diets containing a fixed protein to energy ratio (P:E ratio) of 20.50-mg protein kJˉ¹ GE were fed to triplicate groups of 40 fish (per 70-L tank). Fish were fed 5% of their body weight per day adjusted fortnightly. Diet 1, containing 10% carbohydrate and 17% lipids with a CHO:L ratio of 0.60 produced the poorest (p<0.05) growth rates, feed and protein efficiency. Increasing carbohydrate content in the diets to 26% concomitant with a reduction in lipid content to 11% with a CHO:L ration of 2.29 of diet 5 significantly improved (p<0.05) growth rates, feed and protein efficiency. But did not differ with diet 4, containing CHO:L ratio 2.29. A further increase in dietary carbohydrate up to 31% and a decrease in lipids levels to 9% with a CHO:L ratio ranging from 2.29 to 3.44 (diet 4-5) did not significantly improve the fish performance. Apparent net protein utilisation (ANPU) of fish fed diet 5 was higher (p<0.05) than for diets 1 and 2 but did not differ from diets 3 and 4. Higher lipid deposition (p<0.05) in whole body was observed with decreasing dietary CHO:L ratios as increasing lipid levels. Whole body protein of fish fed varying CHO:L diets did not show any discernible changes among the dietary treatments. This study revealed that H. fossilis can perform equally well on diets containing carbohydrate ranging from 26 to 31%, with 9 to 11% lipid or at CHO:L g/g ratio of 2.29-3.44.

Endothall species selectivity evaluation: northern latitude aquatic plant community

Species selectivity of the aquatic herbicide dipotassium salt of endothall (Aquathol® K) was evaluated on plant species typically found in northern latitude aquatic plant communities. Submersed species included Eurasian watermilfoil (Myriophyllum spicatum L.), curlyleaf pondweed (Potamogeton crispus L.), Illinois pondweed (Potamogeton illinoensis Morong.), sago pondweed (Potamogeton pectinatus L.), coontail (Ceratophyllum demersum L.), elodea (Elodea canadensis Michx.) and wildcelery (Vallisneria americana L.). Emergent and floating-leaf plant species evaluated were cattail (Typha latifolia L.), smartweed (Polygonum hydropiperoides Michx.), pickerelweed (Pontederia cordata L.) and spatterdock (Nuphar advena Aiton). The submersed species evaluations were conducted in 7000 L mesocosm tanks, and treatment rates included 0, 0.5 1.0, 2.0, and 4.0 mg/L active ingredient (ai) endothall (dipotassium salt of endothall). The exposure period consisted of a 24-h flow through half-life for 7 d. The cattail and smartweed evaluation was conducted in 860 L mesocosm tanks, and the spatterdock and pickerelweed evaluations were conducted in 1600 L mesocosm tanks. Treatment rates for the emergent and floating-leafed plant evaluations included 0, 0.5, 2.0 and 4.0 mg/L ai endothall, and the exposure period consisted of removing and replacing half the water from each tank, after each 24 h period for a duration of 120 h. Biomass samples were collected at 3 and 8 weeks after treatment (WAT). Endothall effectively controlled Eurasian watermilfoil and curlyleaf pondweed at all of the application rates, and no significant regrowth was observed at 8 WAT. Sago pondweed, wildcelery, and Illinois pondweed biomass were also significantly reduced following the endothall application, but regrowth was observed at 8 WAT. Coontail and elodea showed no effects from endothall application at the 0.5, 1.0, and 2.0 mg/L application rates, but coontail was controlled at 4.0 mg/L rate. Spatterdock, pickerelweed, cattail, and smartweed were not injured at any of the endothall application rates.

Measures of Plant Surface-areas for Eurasian Watermilfoil and Water Stargrass

Plant surface areas were measured from samples of two common submersed aquatics with widely diverging morphologies: Eurasian watermilfoil ( Myriophyllum spicatum L.) and water stargrass ( Heteranthera dubia (Jacq.) MacM.). Measures for the highly dissected leaves of Eurasian watermilfoil involved development of a regression equation relating leaf length to direct measures of a subsample of leaf parts. Measures for the simple leaves of the stargrass were sums of measured triangles. Stem surfaces for both species were calculated as measured cylinders. Though the means of the stem length and leaf length were larger for stargrass samples, their mean surface area was 95 cm 2 which was less than the 108 cm 2 recorded for Eurasian watermilfoil samples. Relating surface area to dry weight for the stargrass was straightforward, with 1 mg of dry weight yielding an average 0.678 cm 2 of surface area. Biomass measures for the water milfoil were confounded by the additional weight of epiphytic algae persisting on cleaned samples. The results suggest that a lesstime consuming method for surface area measures of plants with highly dissected leaves and a caveat for using biomass measures to estimate surface area in such plants.

Cruise Report 72-S-1: Big Game Fisheries Investigations

(PDF contains 5 pages.)

Life History, Diet, Abundance and Distribution, and Length-Frequencies of Selected Invertebrates in Florida Bay, Everglades National Park, Florida

This report presents information on the life history, diet, abundance and distribution, and length-frequency distributions of five invertebrates in Florida Bay, Everglades National Park. Collections were made with an otter trawl in basins on a bi-monthly basis. Non-parametric statistics were used to test spatial and temporal differences in the abundance of invertebrates when numbers were appropriate (i. e., $25). Invertebrate species are presented in four sections. The sections on Life History, and Diet were derived from the literature. The section on Abundance and Distribution consists of data from otter-trawl collections. In addition, comparisons with other studies are included here following our results. The section on Length-frequency Distributions consists of length measurements from all collections, except 1984-1985 when no measurements were taken. Length-frequency distributions were used, when possible, to estimate life stage captured, spawning times, recruitment into Florida Bay for those species which spawn outside the Bay, and growth. Additional material from the literature was added when appropriate. (PDF contains 39 pages)

Power analysis for detecting trends in juvenile spotted seatrout abundance in Florida Bay

The spotted seatrout (Cynoscion nebulosus) is considered a key species relative to the implementation of the Comprehensive Everglades Restoration Plan (CERP). One of the goals of the CERP is to increase freshwater flows to Florida Bay. Increased freshwater flows can have potential positive and negative impacts on spotted seatrout populations. At low salinities, the planktonic eggs of spotted seatrout sink to the bottom and are not viable (Alshuth and Gilmore, 1994; Holt and Holt, 2002). On the other hand, increased freshwater flows can alleviate hypersaline conditions that could result in an expansion of the distribution of the early life stages of spotted seatrout (Thayer et al., 1999; Florida Department of Environmental Protection1). Thus it would be useful to develop a monitoring program that can detect changes in seatrout abundance on time scales short enough to be useful to resource managers. The NOAA Center for Coastal Fisheries and Habitat Research (NOAA) has made sporadic collections of juvenile seatrout using otter trawls since 1984 (see Powell et al, 2004). The results suggest that it might be useful to sample for seatrout in as many as eight different areas or basins (Figure 1): Bradley Key, Sandy Key, Johnson Key, Palm Key, Snake Bight, Central, Whipray and Crocodile Dragover. Unfortunately, logistical constraints are likely to limit the number of tows to about 40 per month over a period of six months each year. Inasmuch as few seatrout are caught in any given tow and the proportion of tows with zero seatrout is often high, it is important to determine how best to allocate this limited sampling effort among the various basins so that any trends in abundance may be detected with sufficient statistical confidence. (PDF contains 16 pages)

Science-based restoration monitoring of coastal habitats, Volume One: A framework for monitoring plans under the Estuaries and Clean Waters Act of 2000 (Public Law 160-457)

Executive Summary: The Estuary Restoration Act of 2000 (ERA), Title I of the Estuaries and Clean Waters Act of 2000, was created to promote the restoration of habitats along the coast of the United States (including the US protectorates and the Great Lakes). The NOAA National Centers for Coastal Ocean Science was charged with the development of a guidance manual for monitoring plans under this Act. This guidance manual, titled Science-Based Restoration Monitoring of Coastal Habitats, is written in two volumes. It provides technical assistance, outlines necessary steps, and provides useful tools for the development and implementation of sound scientific monitoring of coastal restoration efforts. In addition, this manual offers a means to detect early warnings that the restoration is on track or not, to gauge how well a restoration site is functioning, to coordinate projects and efforts for consistent and successful restoration, and to evaluate the ecological health of specific coastal habitats both before and after project completion (Galatowitsch et al. 1998). The following habitats have been selected for discussion in this manual: water column, rock bottom, coral reefs, oyster reefs, soft bottom, kelp and other macroalgae, rocky shoreline, soft shoreline, submerged aquatic vegetation, marshes, mangrove swamps, deepwater swamps, and riverine forests. The classification of habitats used in this document is generally based on that of Cowardin et al. (1979) in their Classification of Wetlands and Deepwater Habitats of the United States, as called for in the ERA Estuary Habitat Restoration Strategy. This manual is not intended to be a restoration monitoring “cookbook” that provides templates of monitoring plans for specific habitats. The interdependence of a large number of site-specific factors causes habitat types to vary in physical and biological structure within and between regions and geographic locations (Kusler and Kentula 1990). Monitoring approaches used should be tailored to these differences. However, even with the diversity of habitats that may need to be restored and the extreme geographic range across which these habitats occur, there are consistent principles and approaches that form a common basis for effective monitoring. Volume One, titled A Framework for Monitoring Plans under the Estuaries and Clean Waters Act of 2000, begins with definitions and background information. Topics such as restoration, restoration monitoring, estuaries, and the role of socioeconomics in restoration are discussed. In addition, the habitats selected for discussion in this manual are briefly described. (PDF contains 116 pages)

Science-based restoration monitoring of coastal habitats, Volume Two: Tools for monitoring coastal habitats

Healthy coastal habitats are not only important ecologically; they also support healthy coastal communities and improve the quality of people’s lives. Despite their many benefits and values, coastal habitats have been systematically modified, degraded, and destroyed throughout the United States and its protectorates beginning with European colonization in the 1600’s (Dahl 1990). As a result, many coastal habitats around the United States are in desperate need of restoration. The monitoring of restoration projects, the focus of this document, is necessary to ensure that restoration efforts are successful, to further the science, and to increase the efficiency of future restoration efforts.

Juvenile and small resident fishes of Florida Bay, a critical habitat in the Everglades National Park, Florida

This compendium presents information on the life history, diet, and abundance and distribution of 46 of the more abundant juvenile and small resident fish species, and data on three species of seagrasses in Florida Bay, Everglades National Park. Abundance and distribution of fish data were derived from three sampling schemes: (1) an otter trawl in basins (1984–1985, 1994–2001), (2) a surface trawl in basins (1984–1985), and (3) a surface trawl in channels (1984–1985). Results from surface trawling only included pelagic species. Collections made with an otter trawl in basins on a bi-monthly basis were emphasized. Nonparametric statistics were used to test spatial and temporal differences in the abundance of species and seagrasses. Fish species accounts were presented in four sections – Life history, Diet, Abundance and distribution, and Length-frequency distributions. Although Florida Bay is a subtropical estuary, the majority of fish species (76%) had warm-temperate affinities; i.e., only 24% were solely tropical species. The five most abundant species collected, in descending order, by (1) otter trawl in basins were: Eucinostomus gula, Lucania parva, Anchoa mitchilli, Lagodon rhomboides, and Syngnathus scovelli; (2) surface trawl in basins were: Hyporhamphus unifasciatus, Strongylura notata, Chriodorus atherinoides, Anchoa hepsetus, and Atherinomorus stipes; (3) surface trawl in channels were: Hypoatherina harringtonensis, A. stipes, A. mitchelli, H. unifasciatus, and C. atherinoides. (PDF file contains 219 pages.)