Settlement and survival of Chrysaora chesapeakei polyps: implications for adult abundance

2018 ◽  
Vol 601 ◽  
pp. 139-151 ◽  
Author(s):  
S Shahrestani ◽  
H Bi
Keyword(s):  
Adult Abundance

Relationship of upstream migrating adult Atlantic salmon (Salmo salar) and stream discharge within Catamaran Brook, New Brunswick

2007 ◽  
Vol 64 (3) ◽  
pp. 563-573 ◽  
Author(s):  
Sean C Mitchell ◽  
Richard A Cunjak
Keyword(s):  
Body Size ◽  
Atlantic Salmon ◽  
New Brunswick ◽  
Salmo Salar ◽  
Predictive Ability ◽  
River System ◽  
Low Flow ◽  
Stream Discharge ◽  
Atlantic Salmon Salmo Salar ◽  
Adult Abundance

Stream discharge has long been associated with abundance of returning adult spawning salmonids to streams and may also affect body size distribution of adult salmon as low flows interfere with returns of larger-bodied fish. We examined these relationships of abundance and body size within Catamaran Brook, a third-order tributary to the Miramichi River system of New Brunswick, Canada, to investigate the causes of a declining trend in annual returns of Atlantic salmon (Salmo salar) to this stream. Regression models of adult abundance, proportion of the run as grilse, and body size of returning adults as functions of maximum daily stream discharge during the period of upstream spawner migration were constructed. Adult abundance shows a logarithmic relationship with stream discharge and provides good predictive ability, while appearing to not be significantly related to adult abundance in the larger Miramichi system. The proportion as grilse in the run and female body size are also logarithmically related to stream discharge, with low flow years being very influential in the regressions. These relationships of Atlantic salmon population abundance and body size characteristics have implications with respect to stock integrity and production of the following generation.

Importance of philopatry and hydrodynamics in the recruitment of bioeroding sponges on Indonesian coral reefs

2019 ◽  
Vol 70 (6) ◽  
pp. 755
Author(s):  
Joseph Marlow ◽  
Abdul Haris ◽  
James Bell
Keyword(s):  
Coral Reefs ◽  
Large Scale ◽  
Species Assemblage ◽  
Coral Mortality ◽  
Factors Affecting ◽  
Larval Recruitment ◽  
Spatial Coverage ◽  
Reef Degradation ◽  
Adult Abundance ◽  
Cliona Orientalis

Increasingly frequent large-scale coral mortality events are occurring across the globe, leading to a rise in available reef substrata and promoting an increase in the abundance of other benthic taxa. One such group are bioeroding sponges, which can benefit considerably from reef degradation. However, the occupation of new substrates is partially reliant upon larval recruitment, and currently little is known about the factors affecting bioeroding sponge recruitment. In this study we investigated the potential drivers of bioeroding sponge recruitment using a 2-year deployment of experimental calcareous substrates across seven reefs in the Wakatobi region of Indonesia. Recruitment was observed for five bioeroding sponge species, namely Cliona orientalis, Cliothosa cf. aurivillii, Cliothosa hancocki and two presently unidentified brown clionaids, Cliona aff. viridis sp. A and Cliona aff. viridis sp. B. Recruits were present on 69% of the experimental substrates but had a low mean (±s.e.m.) spatial coverage of just 0.42±0.13%. Total recruitment and species assemblage structure were correlated with local adult abundance, water flow and substrate cues. Our results suggest that any proliferation of bioeroding sponges on newly available substrate following coral mortality is likely to be conditional on local adult abundance and hydrodynamics.

Tick (Acari: Ixodidae) ecological studies in Tanzania

1986 ◽  
Vol 76 (2) ◽  
pp. 229-246 ◽  
Author(s):  
R. J. Tatchell ◽  
E. Easton
Keyword(s):  
Seasonal Variation ◽  
Host Density ◽  
Dar Es Salaam ◽  
Rhipicephalus Appendiculatus ◽  
Amblyomma Variegatum ◽  
The Other ◽  
Theileria Parva ◽  
Ecological Studies ◽  
Adult Abundance

AbstractTicks were regularly collected from cattle along transects in Sukumaland and the Southern Highlands, Tanzania, and from locations near Tabora, Mbeya, Arusha and Dar es Salaam from 1973 to 1976. Marked seasonal variation in abundance occurred in Rhipicephalus appendiculatus Neumann in the Southern Highlands (but not in Sukumaland) and in Amblyomma variegatum (F.) near Tabora. It was possible to detect Theileria parva antibodies in cattle sera from the Southern Highlands only during the season of R. appendiculatus adult abundance. Despite this there was no evidence of enzootic instability of the disease. The results demonstrate that the behaviour and distributions of these and the other species of ticks found are not fixed and constant but vary according to a complicated interplay of factors as yet imperfectly understood, such as climate and vegetation and host density, susceptibility and grazing habits.

Hydrodynamic decoupling of recruitment, habitat quality and adult abundance in the Caribbean spiny lobster: source - sink dynamics?

1997 ◽  
Vol 48 (8) ◽  
pp. 807 ◽  
Author(s):  
R. N. Lipcius ◽  
W. T. Stockhausen ◽  
D. B. Eggleston ◽  
L. S. Marshall Jr ◽  
B. Hickey
Keyword(s):  
Habitat Quality ◽  
Large Scale ◽  
Marine Reserve ◽  
Spiny Lobster ◽  
Marine Species ◽  
Nursery Habitat ◽  
Panulirus Argus ◽  
The Caribbean ◽  
Juvenile Density ◽  
Adult Abundance

Marine species possess dispersive stages that interconnect subpopulations, which may inhabit ‘source’ and ‘sink’ habitats, where reproduction and emigration either exceed or fall short of mortality and immigration, respectively. Postlarval supply, juvenile density and adult abundance of the Caribbean spiny lobster, Panulirus argus, were measured at four widely separated sites spanning >100 km in Exuma Sound, Bahamas. Adult abundance was lowest at a site with the highest postlarval supply and little nursery habitat; hence, it was tentatively classified as a sink. Circulation in Exuma Sound is dominated by large-scale gyres which apparently concentrate and advect postlarvae toward the nominal sink. The remaining three sites, including one marine reserve, had higher adult abundances despite lower postlarval supply, and are therefore tentatively classified as sources. Postlarval supply is probably decoupled from adult abundance by physical transport. Adult abundance is likely decoupled from postlarval supply by the effects of varying habitat quality upon postlarval and juvenile survival, as indicated by non-significant differences among sites in juvenile density. It appears that some sites with suitable settlement and nursery habitat are sources of spawning stock for Panulirus argus, whereas others with poor habitat are sinks despite sufficient postlarval influx.

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