Estimation of vertical groundwater fluxes into a streambed through continuous temperature profile monitoring and the relationship of groundwater fluxes to coaster brook trout spawning habitat

We hypothesized that the spatial distribution of groundwater inflows through river bottom sediments is a critical factor associated with the selection of coaster brook trout (a life history variant of Salvelinus fontinalis,) spawning sites. An 80-m reach of the Salmon Trout River, in the Huron Mountains of the upper peninsula of Michigan, was selected to test the hypothesis based on long-term documentation of coaster brook trout spawning at this site. Throughout this site, the river is relatively similar along its length with regard to stream channel and substrate features. A monitoring well system consisting of an array of 27 wells was installed to measure subsurface temperatures underneath the riverbed over a 13-month period. The monitoring well locations were separated into areas where spawning has and has not been observed. Over 200,000 total temperature measurements were collected from 5 depths within each of the 27 monitoring wells. Temperatures within the substrate at the spawning area were generally cooler and less variable than river temperatures. Substrate temperatures in the non-spawning area were generally warmer, more variable, and closely tracked temporal variations in river temperatures. Temperature data were inverted to obtain subsurface groundwater velocities using a numerical approximation of the heat transfer equation. Approximately 45,000 estimates of groundwater velocities were obtained. Estimated velocities in the spawning and non-spawning areas confirmed that groundwater velocities in the spawning area were primarily in the upward direction, and were generally greater in magnitude than velocities in the non-spawning area. In the non-spawning area there was a greater occurrence of velocities in the downward direction, and velocity estimates were generally lesser in magnitude than in the spawning area. Both the temperature and velocity results confirm the hypothesis that spawning sites correspond to areas of significant groundwater influx to the river bed.

Reproductive dynamics of endeavour prawns, Metapenaeus endeavouri and M-ensis, in Albatross Bay, Gulf of Carpentaria, Australia

The spawning patterns of two penaeid prawns, Metapenaeus endeavouri (Schmitt) and M. ensis (De Haan), were examined from data collected at 45 stations between March 1986 and March 1992. An index of population fecundity based on the abundance, proportion and fecundity of sexually mature females was used as a measure of spawning output of the prawn stock. The population fecundity index for M. ensis was higher than that for M. endeavouri. The monthly population fecundity index for M. endeavouri varied markedly among years, while that for M. ensis was consistent among years. Spawning of M. endeavouri occurred year-round, while that of M. ensis was concentrated mainly in spring (September to November). For M. endeavouri, a minor spawning, derived from a relatively small number of summer spawners, occurred in the 20 to 30 m offshore waters in summer. In early summer (after May), the major spawning group consisted of large females from the winter-spawning cohort, and the spawning area shifted to depths of 30 to 60 m. In winter (July), the major spawning, derived from the winter-spawning cohort, occurred at depths of 20 to 40 m. For M. ensis, the major spawning, derived from the spring-spawning cohort, was observed in depths < 50 m and was concentrated particularly in inshore waters ( 50 m). These results suggest that mature female M. endeavouri and M. ensis move offshore (>40 m) by May and July, respectively, and return to shallow waters (

Contribution for a better ecological understanding of the freshwater phase of sea lamprey (Petromyzon marinus) in the Minho River watershed

Dissertação de mestrado em Ecology

08009-005 Storm Lake Watershed Final Report

Storm Lake, the state's fourth largest natural lake, has been the centerpiece of significant economic development, including a resort, water park, and state marina. While there have been considerable improvements to the lake's water quality through a major on-going lake restoration program and watershed project, the Little Storm Lake area still needs to be addressed. Little Storm Lake is a 190 acre area on the nmihwest side of Storm Lake. The water level in both areas is based on the dam height located on the southeast corner of Storm Lake. Approximately 70% of the water from the watershed flows through Little Storm Lake. Little Storm Lake originally had the ability to remove much of the sediment and nutrients from incoming waters. However, due to degradation, proper wetland function has been compromised. Under normal hydrologic conditions Little Storm Lake has the potential to function as a sediment trap for Storm Lake, but tllis capacity is overwhelmed during high flows. Little Storm Lake is at or near its sediment trapping capacity, which results in higher sediment transport into Storm Lake. Resuspension of sediments due to wind and other in-lake dynamics, such as rough fish, further exacerbate the total turbidity from suspended sediment and results in movement of sediment from Little Storm Lake into Storm Lake. This project includes a fish barrier and water retention structure between Little Storm Lake and Storm Lake and the construction of a pumping station and associated equipment. The project involves periodic dewatering of Little Storm Lake during years of favorable climatological conditions to consolidate the sediments and revegetate the area. Construction of the fish banier would aid restoration efforts by preventing rough fish from destroying the vegetation and would decrease recruitment of rough fish by limiting their spawning area. In the future, if the diminished trapping capacity of Little Storm Lake still results in sediment moving into Storm Lake, a dredging project would be initiated to deepen Little Storm Lake.

Biologia reprodutiva de Cyphocharax modestus (Characiformes: Curimatidae) no rio Taquari (alto rio Paranapanema), São Paulo, Brasil

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

Five new records of Luvarus imperialis (Acanthuroidei: Luvaridae) in the south-west Atlantic Ocean

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identificazione di possibili unita' di stock di Anguilla anguilla mediante analisi microchimica e morfometrica degli otoliti

L’anguilla europea, è una specie eurialina catadroma con un complesso ciclo biologico: l’area di riproduzione, unica, si trova molto distante da quella di distribuzione. La specie necessita di una gestione dello stock a fini conservazionistici. Il problema è europeo: lo stock è unico, distribuito in Europa e nell’Africa settentrionale, si riproduce in Atlantico ed è panmittico. C’è preoccupazione per il declino del reclutamento e delle catture di adulti. Lo scopo del progetto è di individuare possibili unità di stock nella penisola italiana. La ricerca è basata sullo studio degli otoliti mediante analisi morfometrica e microchimica. I contorni degli otoliti sono sottoposti ad analisi ellittica di Fourier per individuare eventuali gruppi. Gli otoliti sono stati levigati per effettuare: letture d’età, indagini microstrutturali al SEM delle fasi larvali, analisi microchimiche LA-ICP-MS del nucleo, studiarne l’origine e valutare l’ambiente di sviluppo. Le indagini morfometriche mostrano evidenti pattern ontogenetici, ma non legati ocorrelati alla località, sesso o anno di nascita. Le indagini microstrutturali hanno evidenziano l’alto contenuto organico nucleare, un pattern comune di crescita ed eventi chiave delle fasi larvali, con una media di 212 anelli giornalieri. La microchimica rivela che le larve si sviluppano in acque salate fino alla metamorfosi, poi migrano verso acque meno salate. Le analisi su campioni nati nello stesso anno, evidenziano due gruppi: individui di rimonta naturale e individui di ripopolamento. I profili nucleo bordo evidenziano la permanenza a salinità intermedie degli adulti. L’attività di ricerca si è dimostrata proficua dal punto di vista tecnico con la messa a punto di protocolli innovativi e con forti ricadute sulla riduzione dei tempi e costi d’analisi. Il debole segnale di possibili unità di stock andrà verificato in futuro mediante analisi più dettagliate discriminando meglio la storia di ogni singolo individuo.

Species Assemblages of Leptocephali in the Southwestern Sargasso Sea

Catches of leptocephali of shelf and slope marine eels of the Chlopsidae, Congridae, Moringuidae, Muraenidae, and Ophichthidae collected during a survey in the southwestern Sargasso Sea in late September and early October 1984 were analyzed to learn about their reproductive ecology and larval transport. Sampling along a transect from the Florida Current (FC) out across the southwestern Sargasso Sea and in the Northwest Providence Channel (NWPC) of the Northern Bahamas enabled the evaluation of the larval distributions, abundances and size ranges, regional assemblage structure, and the apparent spawning areas of these marine eels. Distinctly different assemblages observed in the FC and NWPC included the congrid genera Heteroconger, Paraconger, Uroconger, and many ophichthid species, which were rare or absent offshore. Other taxa of congrids, chlopsids, muraenids and moringuids were present in all areas, but the smallest specimens of most taxa were only caught at the NWPC or FC stations. Multivariate analyses reflected higher richness and abundance in the FC and NWPC and also similar species compositions in offshore areas. The patterns of distribution of these leptocephali differed from those of anguillid, nettastomatid, and mesopelagic eel leptocephali collected in the same survey. These findings support the hypothesis that most taxa of marine eels spawn close to their adult habitats, and indicate that despite high biodiversity of marine eels in the Northern Bahamas, only some species of leptocephali appear to get transported far offshore by ocean currents.

Premiers résultats d'une étude quantitative de la reproduction de la sardine dans le Golfe du Lion

In this paper are given the first results of a quantitative study of the spawning of Pilchard Sardina pilchardus in the Gulf of Lion~during Winter 1975 and Winter 1976. The mean density of eggs at each station and their average abundance in the spawning area were estimated. The incubation time of eggs depending upon temperature was also calculated. En 1975 et 1976 une étude de la reproduction de la sardine dans le Golfe du Lion a été réalisée. Les premiers résultats de cette étude, qui a pour but d'évaluer quantitativement la ponte de cette espèce, permettent de donner une estimation moyenne de l'abondance des oeufs au cours d'une campagne. La durée de l'incubation en fonction de la tempé­rature a d'autre part été déterminée.

Ichthyofauna in an estuary of the Mataripe area, Todos os Santos Bay, Bahia, Brazil

The community structure and dynamics as well as some biological parameters of selected species of the ichthyofauna of the Mataripe estuarine region affected by the Landulfo Alves Oil Refinery (RLAM) were analyzed. Twenty stations were sampled with a gillnet in five different periods: August and December 2003, March and July/August 2004 and January 2005. Thirty-five actinopterygian species and one elasmobranch species were recorded, Oligoplites saurus, Diapterus rhombeus, Lutjanus synagris and Scomberomorus brasiliensis among them, on all the campaigns. A total of 1368 specimens, weighing 36.10 kg, were caught. The ichthyofauna total biomass was greater, in weight, on the eastern side of the study region, especially at the stations close to the shoals/reefs and the rocky bottom. A similar pattern was also observed for the diversity values. In general, low evenness and diversity were observed in the area studied, possibly as a result of the fishing gear used. D. rhombeus juveniles dominated in all but one of the samplings (July 2004), in which latter Cyclichthys spinosus was dominant. Carangids and species associated with consolidated bottoms were observed, although in small numbers, throughout the study period. In spite of the limitations imposed by the gear used for sampling, the estuarine area influenced by the RLAM was seen to play a role as a growth area for the great majority of species, especially the mojarra (D. rhombeus), but it offers no fishing potential due to the prevalence of young and small individuals. Evidence of imminent spawning was recorded for Pomadasys corvinaeformis in August 2003, and recent spawning in March 2004 for Oligoplites saurus. Further, mature individuals occurred in insufficient numbers to permit population level evaluation.

Spawning habitat selection by Octopus vulgaris: new insights for a more effective management of this resource

The selection of spawning habitat of a population of Octopus vulgaris that is subject to a small-scale exploitation was studied in the Cíes Islands within the National Park of the Atlantic Islands of Galicia (NW Spain). The technique used was visual censuses by scuba diving. We conducted 93 visual censuses from April 2012 to April 2014. The total swept area was 123.69 ha. Habitat features (season, depth, zone, bottom temperature, swept area, bottom substrate type, and creels fishing impact) were evaluated as predictors of the presence/absence of spawning dens using GAM models. O. vulgaris has a noteworthy preference for spawning in areas with hard bottom substrate and moderate depth (approximately 20 m). The higher density of spawning dens (1.08ha−1) was found in a surveyed area of 50.14ha located in the northeastern part of the northern Cíes Island. We propose to protect the area comprised from Punta Escodelo to Punta Ferreiro between 5 and 30 m depth. This area has a surface of 158 ha equivalent to 5.98% of the total marine area of the Cíes islands. The strengths and weaknesses of a management strategy based on the protection of the species’ spawning habitat are discussed.

Lipid reserves of red mullet (Mullus barbatus) during pre-spawning in the northwestern Mediterranean

Lipid reserves are a particularly important attribute of fishes because they have a large influence on growth, reproduction and survival. This study analyses the lipid content of red mullet (Mullus barbatus) pre-spawners in three different areas of the northwestern Mediterranean in relation to trawling activities and river runoff. The muscle lipid was considered as an indicator of the somatic condition of individuals whilst the gonad lipid was used as a proxy of the energy invested in reproduction. The results show that fish with the highest muscle lipid levels inhabited the area where fishing impact was lowest. Since the abundance and biomass of polychaetes, which represent the main food source for red mullet, were found to be lower in trawled zones than in unfished ones, we suggest that differences in the muscle lipid levels between areas might be attributed to variation in prey abundance in relation to fishing impact. However, no impact of river runoff on lipid reserves of red mullet was observed. The results also show that muscle and gonad lipid reserves are not related to each other during pre-spawning

Effects of artisanal fisheries on the scorpaenids (Scorpaena spp.) reproduction in the marine protected area of Cap de Creus (NW Mediterranean)

Rockfish species are considered important to the ecology of rocky-reef communities which constitute a key habitat in many coastal marine protected areas (MPAs). These species, which are commercially valuable for artisanal fisheries in the Mediterranean, display particular biological traits that could render them vulnerable to fishing. In this study we monitored the artisanal fisheries of scorpaenids (Scorpaena spp.) in the MPA of Cap de Creus (northwestern Mediterranean) in order to estimate the status of their populations, to link captures with the reproduction of these species, and to evaluate the potential impact that artisanal fishing may have on them. Data from onboard sampling with artisanal fishermen and from fisheries statistics (total landings) were used. Total landings and catch per unit of effort (CPUE) follow a clearly seasonal cycle, with a prominent peak during the summer months coinciding with their spawning season, which may be due to mating behavior prior to fertilization. Although maximum sizes are bigger inside the MPA than in non-protected areas situated close by, a significant percentage of individuals caught inside the MPA are below their size at sexual maturity. Although rockfish seem to be favored by the partial protection of the MPA, the allowed artisanal fisheries are probably impacting the reproduction of these species

Reproductive patterns of Aratus pisonii (Decapoda: Grapsidae) from an estuarine area of São Paulo Northern Coast, Brazil

This paper describes the frequency of occurrence and reproductive patterns of the tree mangrove crab Aratus pisonii. Monthly samples were taken from January 1993 to June 1994 in an estuarine mangrove from Ubatuba region, Brazil. A total of 1 078 animals, 489 males and 589 females (131 ovigerous females) were collected. Carapace width ranged from 4.2 to 25.9 mm. A summer reproductive peak followed by a recruitment juvenile pulse was verified. Females were more abundant than males in the intermediate size classes. The sex-ratio in several months was biased towards females, suggesting a poligynous population and migration of females to mangrove fringes at the time of incubation and spawning.

ICHTHYOFAUNA IN AN ESTUARY OF THE MATARIPE AREA, TODOS OS SANTOS BAY, BAHIA, BRAZIL

The community structure and dynamics as well as some biological parameters of selected species of the ichthyofauna of the Mataripe estuarine region affected by the Landulfo Alves Oil Refinery (RLAM) were analyzed. Twenty stations were sampled with a gillnet in five different periods: August and December 2003, March and July/August 2004 and January 2005. Thirty-five actinopterygian species and one elasmobranch species were recorded, Oligoplites saurus, Diapterus rhombeus, Lutjanus synagris and Scomberomorus brasiliensis among them, on all the campaigns. A total of 1368 specimens, weighing 36.10 kg, were caught. The ichthyofauna total biomass was greater, in weight, on the eastern side of the study region, especially at the stations close to the shoals/reefs and the rocky bottom. A similar pattern was also observed for the diversity values. In general, low evenness and diversity were observed in the area studied, possibly as a result of the fishing gear used. D. rhombeus juveniles dominated in all but one of the samplings (July 2004), in which latter Cyclichthys spinosus was dominant. Carangids and species associated with consolidated bottoms were observed, although in small numbers, throughout the study period. In spite of the limitations imposed by the gear used for sampling, the estuarine area influenced by the RLAM was seen to play a role as a growth area for the great majority of species, especially the mojarra (D. rhombeus), but it offers no fishing potential due to the prevalence of young and small individuals. Evidence of imminent spawning was recorded for Pomadasys corvinaeformis in August 2003, and recent spawning in March 2004 for Oligoplites saurus. Further, mature individuals occurred in insufficient numbers to permit population level evaluation.