Aggregations and reproductive events of the narrownose smooth-hound shark (Mustelus schmitti) in relation to temperature and depth in coastal waters of the south-western Atlantic Ocean (38–42°S)

2017 ◽  
Vol 68 (4) ◽  
pp. 732 ◽  
Author(s):  
Mariano Elisio ◽  
Jorge H. Colonello ◽  
Federico Cortés ◽  
Andrés J. Jaureguizar ◽  
Gustavo M. Somoza ◽  
...  
Keyword(s):  
Water Temperature ◽  
Coastal Waters ◽  
Temperature Increase ◽  
Environmental Influence ◽  
Effective Management ◽  
Bottom Temperature ◽  
Western Atlantic ◽  
Variability Pattern ◽  
Reproductive Events ◽  
Mustelus Schmitti

Knowledge of environmental influence on reproductive dynamics in chondrichthyans is critical for effective management. The present study assessed the potential influences of temperature and depth on aggregations and reproductive events of the narrownose smooth-hound shark (Mustelus schmitti), using an analysis criterion based on the co-occurrence of different reproductive stages. Data were collected from 363 sample sites during six research surveys, covering an area of ~47744km2 along the coast (38–42°S, depth of <50m). Aggregations of M. schmitti adults were mostly associated with the warmer spring surveys, with the aggregation sites being significantly warmer than those of non-aggregation. Evidence of pupping and ovulation was observed, almost simultaneously, during all spring surveys. However, the occurrence of these reproductive events showed a clear interannual variability pattern that was significantly explained by water temperature. Particularly, the occurrence of ovulation was associated with temperatures above 16–17°C. These results suggest that M. schmitti adults may follow the warming gradient along the environment and, thus, they aggregate in shallow and productive waters during the course of spring. Their reproductive events could be induced by temperature increase. This scenario suggests that changes in the patterns of bottom temperature may be important drivers of the reproductive dynamics of M. schmitti.

scholarly journals Morphology and ecology of Thalassiosira Cleve (Bacillariophyta) species rarely recorded in Brazilian coastal waters

2009 ◽  
Vol 69 (4) ◽  
pp. 1059-1071 ◽  
Author(s):  
M. Garcia ◽  
C. Odebrecht
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Water Temperature ◽  
Wide Temperature Range ◽  
Coastal Waters ◽  
Light Microscope ◽  
Temperature Range ◽  
The World ◽  
First Time ◽  
Scanning Electron

The detailed description of rarely recorded Thalassiosira species in Brazil is presented with light microscope (LM) and scanning electron microscope (SEM) illustrations. A total of 78 phytoplankton net samples (20 µm) collected between the years 2000 and 2006 in coastal waters of southern Brazilian, Cassino Beach and the estuary of Lagoa dos Patos, were studied in cleaned material using the Axiovert Zeiss LM and Jeol 6060 SEM. Water temperature and salinity of samples and six species are presented: Thalassiosira endoseriata, T. hendeyi, T. lundiana, T. minuscula, T. oceanica and T. wongii. Two species, Thalassiosira hendeyi and T. endoseriata were the most common being observed in all seasons at Cassino Beach in a wide temperature range (10-26 ºC), while only sporadically in the estuary of Lagoa dos Patos. Thalassiosira endoseriata, T. lundiana, T. oceanica and T. wongii are for the first time reported in Brazilian coastal waters. The latter two species, rarely recorded in the world, are fully illustrated based on Brazilian material.

Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

2007 ◽  
Keyword(s):  
Water Temperature ◽  
Coastal Waters ◽  
Fork Length ◽  
The United States ◽  
Nursery Habitat ◽  
Tiger Shark ◽  
Carcharhinus Plumbeus ◽  
Species Area ◽  
Catch Rates ◽  
Mustelus Canis

<em>Abstract.</em>—To identify and characterize shark nursery habitat in the coastal waters of Massachusetts, longline and shark angler surveys were conducted from 1989 to 2002 in the neritic waters of Nantucket Sound, Massachusetts. Additional samples and information were opportunistically collected from recreational and commercial fishermen, as well as published sources. A total of 123 longline sets of 5,591 hooks caught 372 sharks consisting of 344 (92.5%) smooth dogfish <em>Mustelus canis</em>, 23 (6.2%) sandbar sharks <em>Carcharhinus plumbeus</em>, and 5 (1.3%) dusky sharks <em>C. obscurus</em>. The sharks were taken during the period of 16 June–24 September in water temperature and depth ranges of 16.0–27.2°C and 1.2–27.1 m, respectively. Longline catch rates (number of sharks per longline set) were stratified by species, area, month, year, water temperature, and depth. Angler surveys reported the capture of 294 sharks, including sandbar sharks (72%) and smooth dogfish (28%). Data from 540 neonatal and adult smooth dogfish ranging 27.5–121.0 cm fork length (FL) support the conclusion that the neritic waters of southern Massachusetts serve as primary nursery habitat for this species. Size and sex data from 235 juvenile sandbar sharks ranging 61.0–157.0 cm FL indicate that this region provides secondary nursery habitat for this species. Opportunistic samples of juvenile sand tiger <em>Carcharias taurus</em>, white shark <em>Carcharodon carcharias</em>, basking shark <em>Cetorhinus maximus</em>, and tiger shark <em>Galeocerdo cuvier </em>provide evidence that these species utilize Massachusetts coastal waters for secondary nursery habitat.

New light on the nomenclature, taxonomy, and biology of Hemipholis species (Echinodermata: Ophiuroidea: Ophiactidae)

Zootaxa ◽  
2011 ◽  
Vol 3048 (1) ◽  
pp. 44 ◽  
Author(s):  
GORDON HENDLER
Keyword(s):  
Water Temperature ◽  
Cold Tolerance ◽  
Coastal Water ◽  
Brittle Star ◽  
Eastern Pacific ◽  
Warm Water ◽  
Western Atlantic ◽  
Boundary Currents ◽  
Incertae Sedis ◽  
Nomen Novum

Hemipholis cordifera is the correct name for the only known Western Atlantic species of Hemipholis. Hemipholis elongata, a name which has been used in place of H. cordifera, is a nomen dubium that cannot unambiguously be assigned to any known species of brittle star. Evidence is presented that the genus Hemipholis presently comprises only H. cordifera and its geminate Eastern Pacific congener Hemipholis gracilis, and it is shown that the latter name has priority over Hemipholis affinis. Hemipholis gracilis and H. cordifera are illustrated and compared to show how mature individuals can be distinguished. However, small individuals of both species are extremely similar. The latitudinal distributions of H. cordifera and H. gracilis appear to be causally related to coastal water temperature, possibly in conjunction with divergent ocean currents, and the relatively broad range of H. cordifera compared to H. gracilis is attributed to its cold tolerance and to the influence of widespread warm-water boundary currents in the central Western Atlantic. As regards the two other congeners that have been described, Hemipholis wallichii is revealed to be a juvenile ophiuroid incertae sedis, and Hemipholis microdiscus was previously transferred to the Amphiuridae and assigned the nomen novum, Amphiura microdiscoida.

Utilization of nitrogen and carbon by phytoplankton in Moreton Bay, Australia

2000 ◽  
Vol 51 (7) ◽  
pp. 703 ◽  
Author(s):  
M. J. O'Donohue ◽  
P. M. Glibert ◽  
W. C. Dennison
Keyword(s):  
Water Temperature ◽  
Coastal Waters ◽  
Inorganic Nitrogen ◽  
Spatial Scales ◽  
Co2 Uptake ◽  
Phytoplankton Productivity ◽  
Moreton Bay ◽  
Uptake Rates ◽  
Temporal And Spatial ◽  
River Mouths

Water samples were collected within river mouths, at river plume sites and at well flushed ocean-influenced sites within Moreton Bay, a shallow subtropical embayment in south-eastern Queensland. Rates of inorganic nitrogen (NH+4 and NO-3) and carbon uptake were determined across temporal and spatial scales by use of 15N and 14C incorporation. Phytoplankton productivity, measured as CO2 uptake, was highest at the river mouths. Rates of NH+4 uptake exceeded rates of NO-3 uptake at all sites at all times. Relative preference indices demonstrated a consistent preference by phytoplankton for NH+4 uptake, and NH+4 uptake rates were higher at ocean-influenced sites than at river-mouth sites. Inorganic nutrient and chlorophyll a concentrations were highest at river mouths; however, the greatest NH+4 uptake occurred at the ocean-influenced sites, reflecting a greater dependence on ‘recycled’ N than on ‘new’ N. Biomass-independent NH+4 uptake increased with increasing water temperature; however, NO-3 uptake increased with decreasing water temperature, reflecting the lower temperature optimum for nitrate reductase. The range of NH+4 and NO-3 uptake rates was greater than ranges reported for other coastal waters, reflecting the strong temporal and spatial gradients within Moreton Bay. This trend of strong gradients in C and N dynamics from oligotrophic to river-influenced waters with seasonal flows is likely to exist in many tropical and subtropical coastal waters of Australia.

Evidence for thermally mediated settlement in lobster larvae (Homarus americanus)

2013 ◽  
Vol 70 (11) ◽  
pp. 1641-1649 ◽  
Author(s):  
Eric R. Annis ◽  
Carl J. Wilson ◽  
Robert Russell ◽  
Philip O. Yund
Keyword(s):  
Water Temperature ◽  
Settlement Patterns ◽  
Coastal Region ◽  
Homarus Americanus ◽  
Size Increase ◽  
Coastal Current ◽  
Bottom Temperature ◽  
Degree Days ◽  
Successful Recruitment ◽  
Behavioral Avoidance

We examined the potential for bottom temperatures ≤12 °C to inhibit successful recruitment of planktonic lobster postlarvae to the benthos. In laboratory trials, postlarvae held at 11 °C exhibited higher mortality, slower development, and reduced size increase at molt relative to postlarvae held at 13 °C. We sampled at field sites within Machias Bay, Maine (mean bottom temperature 12.39 °C, 46.1 degree-days ≥12 °C) and at the mouth of the bay (mean bottom temperature 11.57 °C, 5.1 degree-days ≥12 °C), where temperature was influenced by the cold Eastern Maine Coastal Current (EMCC). We found significantly higher settlement at the warm inshore site but, the abundance of competent planktonic postlarvae was not significantly different between sites, indicating a disconnect between postlarval abundance and settlement. Regional sampling of newly settled lobsters revealed a pattern of higher settlement at inshore sites extending across a broader coastal region impacted by the EMCC. Our results suggest that small differences in water temperature may shape settlement patterns through either behavioral avoidance of colder settlement sites or elevated postsettlement mortality of postlarvae settling at colder sites.

Study on the Impact of Water Environmental Factors on Dominant Species of Phytoplankton around the Power Plant in Xiangshan Bay

2012 ◽  
Vol 610-613 ◽  
pp. 3371-3374 ◽  
Author(s):  
Hong Yang ◽  
Ying Zhao ◽  
Hui Rong Zhang ◽  
Gui Xiang Dai ◽  
Jun Ding ◽  
...  
Keyword(s):  
Power Plant ◽  
Environmental Factors ◽  
Statistical Model ◽  
Water Temperature ◽  
Temperature Increase ◽  
Dominant Species ◽  
Thermal Discharge ◽  
Xiangshan Bay ◽  
The Impact ◽  
Growth And Reproduction

The SPSS19.0 software was used to analyse the data of enclosure experiments last for 7 days in summer of 2011. Water temperature increase as a factor to establish the statistical model, and the response relation of thermal discharge warming and Coscinodiscus Jonesianus biomass was analyzed quantitatively. The results showed that, it would promote Coscinodiscus Jonesianus growth and reproduction with the water warming at 0.2°C to 0.79°C , which would be restrained at the water warming at 0.8°C to 2.0°C. When the water temperature increase 0.1°C, 0.4°C and 0.7°Cwill respectively result in Coscinodiscus Jonesianus biomass grow 216.12%, 72.87% and 15.05%. While the water temperature increase 1.0°C, 1.5°C and 2.0°C will respectively result in Coscinodiscus Jonesianus biomass reduce 6.38%, 17.95% and 26.17%.

Evidence for water temperature increase in Lake George, NY: impact on growing season duration and degree days

2015 ◽  
Vol 31 (3) ◽  
pp. 241-253 ◽  
Author(s):  
Mark W. Swinton ◽  
Lawrence W. Eichler ◽  
Jeremy L. Farrell ◽  
Charles W. Boylen
Keyword(s):  
Water Temperature ◽  
Temperature Increase ◽  
Growing Season ◽  
Degree Days ◽  
Lake George

Anadromous Arctic Char, Salvelinus alpinus, Penetrating Southward on the Norwegian Coast

1981 ◽  
Vol 38 (2) ◽  
pp. 247-249 ◽  
Author(s):  
John Willas Jensen
Keyword(s):  
Water Temperature ◽  
Coastal Waters ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Distribution Area ◽  
Glacial Period ◽  
Dense Population ◽  
Last Glacial Period ◽  
Norwegian Coast ◽  
The Last Glacial

Anadromous Arctic char, Salvelinus alpinus, have been limited on the Norwegian coast to areas north of 65°N. In 1967 anadromous char invaded the river Granvinelv in the Hardangerfjord at 60°N, and have given rise to a dense population of stationary freshwater char in the lake Granvinvatn. During 1978–79 anadromous char spread to several rivers at the head of the fjord. Events assumed to have taken place during the melting-off phase of the last glacial period are recurring. The Hardangerfjord is colder than the outside coastal waters and will very probably function as a subarea of the char. The available data indicates that an average coastal water temperature of 14 °C at 4–5 m depth is limiting the anadromous char to the south on the Norwegian coast. Continuous water masses colder than 13.6 °C could have permitted the southward penetration of anadromous char to the Hardangerfjord in 1964, but the char may also have escaped from a hatchery in the vicinity of the fjord. Landlocked char of a river entering the head of the Hardangerfjord evidently do not possess the capacity to give rise to an anadromous population.Key words: Salvelinus alpinus, anadromous char, distribution area, southward penetration, temperature barrier

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