Environmental influences on the larval recruitment dynamics of snapper, Chrysophrys auratus (Sparidae)

2013 ◽  
Vol 64 (8) ◽  
pp. 726 ◽  
Author(s):  
Carina J. Sim-Smith ◽  
Andrew G. Jeffs ◽  
Craig A. Radford
Keyword(s):  
Environmental Variables ◽  
High Water ◽  
Pelagic Larval Duration ◽  
Tidal Range ◽  
Good Survival ◽  
Larval Abundance ◽  
Larval Duration ◽  
Spawning Period ◽  
Larval Recruitment ◽  
Recruitment Success

Recruitment success in demersal fish species that settle in estuaries after a pelagic larval duration in coastal waters is dependent on (1) abiotic and biotic variables that promote good survival, and (2) local environmental conditions that facilitate and direct the transport of larvae to settlement habitats. In the present study, we described the patterns of larval abundance, pelagic larval duration and settlement of a commercially important sparid, Chrysophrys auratus, in northern New Zealand over 2 years, and investigated the relationships among pelagic larval duration or daily settler abundance and various environmental variables. Pelagic larval duration varied from 17 to 33 days and the successful spawning period that produced settled juveniles varied from 29 to 109 days among our four sites. For 91% of fish captured, the average temperature during the pelagic larval duration was >18°C. Significant correlations between daily settler abundance and environmental variables varied among sites and between years; however, temperature, tidal range and on-shore winds were most strongly correlated with settlement, explaining up to 38% of the variability in settler abundance. The present results suggested that, in some locations, high water temperatures, large tides and on-shore winds are likely to increase recruitment success in C. auratus.

scholarly journals Coastal winds drive a recruitment mechanism for estuarine fisheries

2020 ◽  
Author(s):  
Hayden T. Schilling ◽  
Charles Hinchliffe ◽  
Jonathan P. Gillson ◽  
Anthony Miskiewicz ◽  
Iain M. Suthers
Keyword(s):  
Larval Fish ◽  
Future Research ◽  
Larval Abundance ◽  
Spawning Period ◽  
Onshore Wind ◽  
Larval Recruitment ◽  
Australian Region ◽  
Coastal Winds ◽  
Key Driver ◽  
Catch Rates

AbstractCoastal winds transport larval fish onshore or offshore which may contribute to estuarine recruitment, yet our understanding of the mechanism underlying this relationship is limited. Here, we show that larval abundance of coastally spawned species increased with weak to moderate upwelling favourable winds 14 days prior to sampling, reflecting increased nutrient and plankton availability for larval fish. A strong decline in larval abundance was observed following strong upwelling favourable winds while abundance increased with onshore (downwelling favourable) winds, in relation to offshore and onshore wind-driven transport. Subsequently, we show that effects of wind during the spawning period can be detected in lagged estuarine commercial fisheries catch rates of coastally spawned species (lagged by 2 – 8 years depending on species’ growth rates), representing the same mechanism proposed for larval fish. Upwelling favourable winds in the southeast Australian region have increased since 1850 while onshore winds have decreased, which may reduce larval recruitment to estuaries. Coastal winds are likely an important factor for estuarine recruitment in the east Australian region and future research on the estuarine recruitment of fish should incorporate coastal winds. As global winds are changing, it is important to investigate if this mechanism is applicable to other regions around the world where coastal winds are a key driver of upwelling.

scholarly journals Structure, Diversity, and Environmental Determinants of High-Latitude Threatened Conifer Forests

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 775
Author(s):  
Carlos Esse ◽  
Francisco Correa-Araneda ◽  
Cristian Acuña ◽  
Rodrigo Santander-Massa ◽  
Patricio De Los Ríos-Escalante ◽  
...  
Keyword(s):  
Water Table ◽  
Environmental Variables ◽  
National Park ◽  
High Water ◽  
Forest Communities ◽  
Competitive Effect ◽  
Forest Patches ◽  
Last Glaciation ◽  
The World ◽  
Local Topography

Pilgerodendron uviferum (D. Don) Florin is an endemic, threatened conifer that grows in South America. In the sub-Antarctic territory, one of the most isolated places in the world, some forest patches remain untouched since the last glaciation. In this study, we analyze the tree structure and tree diversity and characterize the environmental conditions where P. uviferum-dominated stands develop within the Magellanic islands in Kawésqar National Park, Chile. An environmental matrix using the databases WorldClim and SoilGrids and local topography variables was used to identify the main environmental variables that explain the P. uviferum-dominated stands. PCA was used to reduce the environmental variables, and PERMANOVA and nMDS were used to evaluate differences among forest communities. The results show that two forest communities are present within the Magellanic islands. Both forest communities share the fact that they can persist over time due to the high water table that limits the competitive effect from other tree species less tolerant to high soil water table and organic matter. Our results contribute to knowledge of the species’ environmental preference and design conservation programs.

Intraspecific variation in the pelagic larval duration of tropical reef fishes

2006 ◽  
Vol 68 (4) ◽  
pp. 1206-1214 ◽  
Author(s):  
L. K. Bay ◽  
K. Buechler ◽  
M. Gagliano ◽  
M. J. Caley
Keyword(s):  
Intraspecific Variation ◽  
Reef Fishes ◽  
Pelagic Larval Duration ◽  
Larval Duration ◽  
Tropical Reef

Stretched to the limit; can a short pelagic larval duration connect adult populations of an Indo-Pacific diadromous fish (Kuhlia rupestris)?

2013 ◽  
Vol 22 (6) ◽  
pp. 1518-1530 ◽  
Author(s):  
P. Feutry ◽  
A. Vergnes ◽  
D. Broderick ◽  
J. Lambourdière ◽  
P. Keith ◽  
...  
Keyword(s):  
Pelagic Larval Duration ◽  
Larval Duration ◽  
Diadromous Fish

The larval, juvenile, and adult stages of the Caribbean goby, Coryphopterus kuna (Teleostei: Gobiidae): a reef fish with a pelagic larval duration longer than the post-settlement lifespan

Zootaxa ◽  
2010 ◽  
Vol 2346 (1) ◽  
pp. 53-61
Author(s):  
BENJAMIN C. VICTOR ◽  
LOURDES VASQUEZ-YEOMANS ◽  
MARTHA VALDEZ-MORENO ◽  
LESLIE WILK ◽  
DAVID L. JONES ◽  
...  
Keyword(s):  
Pelagic Larval Duration ◽  
Age And Growth ◽  
Quintana Roo ◽  
Larval Duration ◽  
Western Atlantic ◽  
Dorsal Fin ◽  
Pelagic Larvae ◽  
The Caribbean ◽  
Southern Florida ◽  
San Andres

Additional larval, juvenile, and adult specimens and live photographs of the Caribbean Kuna Goby, Coryphopterus kuna, expand the known geographic range for the species and allow a comprehensive description of all the life stages for this recently-discovered species, including age and growth estimates from daily otolith increments. The Kuna Goby is found widely throughout the tropical western Atlantic, including southern Florida, Quintana Roo on the Yucatan Peninsula of Mexico, Belize, Honduras, Panama, San Andres Island, Bonaire, and Guadeloupe. The additional specimens indicate that C. kuna has a pelvic frenum and that females have a black flag on the outer portion of the first two spinous dorsal-fin membranes, while males have a dark stripe along the mid-length of the spinous dorsal fin. The development of melanophores on pelagic larvae through the transition to settled juvenile is described. The Kuna Goby is a notably small goby: larvae settle around 7–9 mm SL, adults mature at 10–11 mm SL and then only attain about 17 mm SL. Kuna Gobies settle after a 60-day pelagic larval life, and mature rapidly. They are reproductive in as few as three weeks and live for about two months after settlement. This is the first reported fish in which the pelagic larval duration is generally longer than the post-settlement lifespan.

scholarly journals Effects of climate and spawning stock structure on the spatial distribution of Northeast Arctic cod larvae

2020 ◽  
Author(s):  
Clarissa Akemi Kajiya Endo ◽  
Frode B Vikebø ◽  
Natalia A Yaragina ◽  
Solfrid Sætre Hjøllo ◽  
Leif Christian Stige
Keyword(s):  
Spatial Distribution ◽  
Environmental Variables ◽  
Barents Sea ◽  
Condition Index ◽  
Ocean Current ◽  
Larval Abundance ◽  
Near Surface ◽  
Spawning Stock ◽  
Long Time ◽  
Abundance And Distribution

Abstract The spatial distribution of fish early life stages can impact recruitment at later stages and affect population size and resilience. Northeast Arctic (NEA) cod spawning occurs along the Norwegian coast. Eggs, larvae, and pelagic juveniles drift near-surface towards the Barents Sea nursery area. In this study, a 35-year long time series of NEA cod larvae data was analysed in combination with factors that potentially may affect the distribution of eggs and larvae. These factors included biological aspects of the spawning stock, and environmental variables, such as water temperature, wind, ocean current, and prey abundance. Our aim was to shed light on how these factors influence larval abundance and distribution and how larval abundance and distribution influenced recruitment at age 3. We found that biomass and mean weight of the spawners were positively associated with larval abundance and that a high liver condition index of the spawners was associated with a north-easterly distribution of the larvae. The environmental variables showed generally weak or no correlations with abundance or distribution of larvae. Lastly, we found significant association between larval abundance and year-class abundance at age 3, while the spatial distribution metrics of the larvae, i.e. distribution extent, mean longitude, and mean latitude, showed no significant association with future year-class abundance.

scholarly journals Assessing macroinvertebrate communities in relation to environmental variables: the case of Sambandou wetlands, Vhembe Biosphere Reserve

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatenda Dalu ◽  
Rivoningo Chauke
Keyword(s):  
Community Structure ◽  
Water Depth ◽  
Environmental Variables ◽  
Anthropogenic Activities ◽  
Biosphere Reserve ◽  
High Water ◽  
Macroinvertebrate Community ◽  
Macroinvertebrate Communities ◽  
Negative Effect ◽  
Macrophyte Cover

AbstractThe Vhembe Biosphere Reserve, South Africa, contains many wetlands that serve as wildlife habitats and provide vital ecosystem services. Some of the wetlands are continuously being degraded or destroyed by anthropogenic activities causing them to disappear at an alarming rate. Benthic macroinvertebrates are known as good water quality bioindicators and are used to assess aquatic ecosystem health. The current study investigated habitat quality using macroinvertebrate community structure and other biotic variables (i.e. phytoplankton, macrophytes) in relation to environmental variables in the Sambandou wetlands using canonical correspondence analysis (CCA). A total of fifteen macroinvertebrate families were identified over two seasons. The CCA highlighted seven variables, i.e. pH, phosphate concentration, temperature, ammonium, macrophyte cover, conductivity and water depth, which were significant in structuring macroinvertebrate community. Picophytoplankton and microphytoplankton concentrations decreased from winter to summer, whereas nanophytoplankton concentration increased from winter to summer. Thus, the dominance of small-sized phytoplankton indicated nutrient limitation and decreased productivity, whereas winter sites 2 and 3 were dominated by large-celled phytoplankton, highlighting increased productivity. Winter sites were mostly negatively associated with CCA axis 1 and were characterised by high temperature, phosphate and ammonium concentrations, macrophyte cover, pH and conductivity. Summer sites were positively associated with axis 1, being characterised by high water depth and pH levels. The results obtained highlighted that agricultural activities such as cattle grazing and crop farming and sand mining/poaching had a negative effect on macroinvertebrate community structure.

Coryphopterus kuna, a new goby (Perciformes: Gobiidae: Gobiinae) from the western Caribbean, with the identification of the late larval stage and  an estimate of the pelagic larval duration

Zootaxa ◽  
2007 ◽  
Vol 1526 (1) ◽  
pp. 51-61 ◽  
Author(s):  
BENJAMIN C. VICTOR
Keyword(s):  
Larval Stage ◽  
Gene Sequence ◽  
Pelagic Larval Duration ◽  
Larval Duration ◽  
Sequence Matching ◽  
Daily Increments ◽  
Black Spots ◽  
Fin Ray ◽  
Western Caribbean ◽  
Pelvic Fin

A new goby, Coryphopterus kuna, is described from the Atlantic coasts of Panama and Mexico. The species is distinguished from other Coryphopterus spp. by the low median fin and pectoral fin ray counts and the morphology of the pelvic fin. The pelvic fins are fully joined with a rounded outline and have branched and longer innermost pelvic fin rays. There is no frenum connecting the two pelvic fin spines and the fin is heavily speckled with black spots in the male holotype. The late larval stage of C. kuna is identified by DNA sequence matching and is morphologically similar to other larval Coryphopterus spp. but has a distinct melanophore pattern. Examination of the otolith microstructure reveals a relatively long pelagic larval duration of 63 days with a narrowing of the later daily increments suggesting delayed metamorphosis. The species is the first vertebrate to include gene sequence barcoding under the Barcode of Life Data System (BOLD) in the species description.

Uncertainty in coastal flooding: modelling and visualisation

2020 ◽  
Author(s):  
John Maskell
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
Return Period ◽  
Flood Risk ◽  
High Water ◽  
Coastal Flooding ◽  
Water Levels ◽  
Tidal Range ◽  
The Uk ◽  
Flood Maps

<p>Two case studies are considered in the UK, where uncertainty and drivers of coastal flood risk are explored through modelling and visualisations. Visualising the impact of uncertainty is a useful way of explaining the potential range of predicted or simulated flood risk to both expert and non-expert stakeholders.</p><p>Significant flooding occurred in December 2013 and January 2017 at Hornsea on the UK East Coast, where storm surge levels and waves overtopped the town’s coastal defences. Uncertainty in the potential coastal flooding is visualised at Hornsea due to the range of uncertainty in the 100-year return period water level and in the calculated overtopping due to 3 m waves at the defences. The range of uncertainty in the simulated flooding is visualised through flood maps, where various combinations of the uncertainties decrease or increase the simulated inundated area by 58% and 82% respectively.</p><p>Located at the mouth of the Mersey Estuary and facing the Irish Sea, New Brighton is affected by a large tidal range with potential storm surge and large waves. Uncertainty in the coastal flooding at the 100-year return period due to the combination of water levels and waves is explored through Monte-Carlo analysis and hydrodynamic modelling. Visualisation through flood maps shows that the inundation extent at New Brighton varies significantly for combined wave and surge events with a joint probability of 100 years, where the total flooded area ranges from 0 m<sup>2</sup> to 10,300 m<sup>2</sup>. Waves are an important flood mechanism at New Brighton but are dependent on high water levels to impact the coastal defences and reduce the effective freeboard. The combination of waves and high-water levels at this return level not only determine the magnitude of the flood extent but also the spatial characteristics of the risk, whereby flooding of residential properties is dominated by overflow from high water levels, and commercial and leisure properties are affected by large waves that occur when the water level is relatively high at the defences.</p>

The nature and significance of microatolls

1978 ◽  
Vol 284 (999) ◽  
pp. 99-122 ◽  
Keyword(s):  
Open Water ◽  
High Water ◽  
Growth Direction ◽  
Tidal Range ◽  
Water Interface ◽  
Maximum Elevation ◽  
Two Factors ◽  
Upward Growth ◽  
Daily Water ◽  
Water Springs

Microatolls, those coral colonies with dead, flat tops and living perimeters, result from a restriction of upward growth by the air/water interface. The principal growth direction is horizontal and is recorded in the internal structure, though fluctuations in water depth can influence the surface morphology producing a terraced effect. The morphology of the basal surface of the colony is controlled by the sand/water interface such that the thickness of the coral records the depth of water in which it lived. In open water at the margin of reefs in the Northern Province of the Great Barrier Reef, tall-sided uneven-topped microatolls live, whereas, on the reef flats in rampart-bounded moats and ponds, thin flat-topped and terraced microatolls are abundant. Because water in moats can be ponded to levels as high as high water neaps (1.6 m above datum at Cairns) and still have daily water replenishment, microatolls on reef flats can grow to levels 1.1 m higher than open-water microatolls (which grow up to a maximum elevation of low water springs, i.e. 0.5 m above datum). This imposes a major constraint on the use of microatolls in establishing sea level history. The two factors controlling pond height during one sea stand (relative to the reef) are tidal range (which governs the height of high water neaps) and wave energy (which governs the height of ramparts which enclose moats). Dating and levelling fossil microatolls exposed on the reefs show that 4000 years (a) B.P., high water neaps was at least 0.7 m higher than it is at present.

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