scholarly journals Spatial variation in the structure of overwintering, remnant Saccorhiza polyschides sporophytes and their associated assemblages

2021 ◽  
pp. 1-10
Author(s):  
Nora Salland ◽  
Dan Smale
Keyword(s):  
Habitat Structure ◽  
Wave Exposure ◽  
Marine Ecology ◽  
Taxon Richness ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Saccorhiza Polyschides ◽  
Fundamental Goal ◽  
Internal Volume ◽  
The Uk

Abstract Understanding the structure and richness of natural communities is a fundamental goal of marine ecology, and foundation species such as large macroalgae have a disproportionate role in structuring biodiversity. However, high-resolution information on assemblages associated with macroalgae is lacking for many species and regions. Saccorhiza polyschides is a warm-temperate kelp with a relatively short lifespan (12–18 months), large thallus and bulbous holdfast offering habitat for diverse assemblages. In the UK, S. polyschides populations are thought to have proliferated recently. Here, we quantified the density and habitat structure provided by S. polyschides along a gradient of wave exposure within Plymouth Sound, and examined the composition and diversity of associated faunal assemblages. Density varied significantly between sites but not by wave exposure, while biometric measurements were generally highly variable. Senescing holdfasts from sporophytes offered valuable habitat, with high abundance and richness of associated assemblages, although these varied markedly between sporophytes and sites. Faunal abundance, taxon richness and diversity were significantly higher at fully exposed sites than at moderately exposed sites. Internal volume of holdfasts was positively correlated with faunal abundance and taxon richness. We recorded more than 27 distinct taxa and up to ~600 individuals within a single holdfast. Taxa included three fish species, including a novel observation of the pipefish Nerophis lumbriciformis. Further work is needed to examine seasonality in habitat structure and associated diversity patterns but our study demonstrates that even remnant holdfasts from decaying sporophytes represent a valuable microhabitat that may provide shelter, protection and food during winter.

scholarly journals The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs

2009 ◽  
Vol 66 (4) ◽  
pp. 691-698 ◽  
Author(s):  
W. R. Hunter ◽  
M. D. J. Sayer
Keyword(s):  
Habitat Complexity ◽  
Artificial Reef ◽  
Structural Complexity ◽  
Marine Species ◽  
Rocky Reef ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Concrete Blocks ◽  
Belt Transect ◽  
Natural Reefs

Abstract Hunter, W. R., and Sayer, M. D. J. 2009. The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs. – ICES Journal of Marine Science, 66: 691–698. Several north temperate marine species were recorded on subtidal hard-substratum reef sites selected to produce a gradient of structural complexity. The study employed an established scuba-based census method, the belt transect. The three types of reef examined, with a measured gradient of increasing structural complexity, were natural rocky reef, artificial reef constructed of solid concrete blocks, and artificial reef made of concrete blocks with voids. Surveys were undertaken monthly over a calendar year using randomly placed fixed rope transects. For a number of conspicuous species of fish and invertebrates, significant differences were found between the levels of habitat complexity and abundance. Overall abundance for many of the species examined was 2–3 times higher on the complex artificial habitats than on simple artificial or natural reef habitats. The enhanced habitat availability produced by the increased structural complexity delivered through specifically designed artificial reefs may have the potential to augment faunal abundance while promoting species diversity.

scholarly journals Macroalgae contribute to the diet of Patella vulgata from contrasting conditions of latitude and wave exposure in the UK

2016 ◽  
Vol 549 ◽  
pp. 113-123 ◽  
Author(s):  
GM Notman ◽  
RAR McGill ◽  
SJ Hawkins ◽  
MT Burrows
Keyword(s):  
Wave Exposure ◽  
Patella Vulgata ◽  
The Uk

scholarly journals Do beds of subtidal estuarine seagrass constitute a refuge for macrobenthic biodiversity threatened intertidally?

2020 ◽  
Vol 29 (11-12) ◽  
pp. 3227-3244 ◽  
Author(s):  
R. S. K. Barnes ◽  
L. Claassens
Keyword(s):  
National Park ◽  
Single Species ◽  
Seagrass Habitat ◽  
Taxonomic Distinctness ◽  
Intertidal Zones ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Macrobenthic Assemblages ◽  
First Time ◽  
Assemblage Metrics

Abstract Biodiversity differentials between macrobenthic assemblages associated with adjacent intertidal and subtidal areas of a single seagrass system were investigated for the first time. Assemblage metrics of conservation relevance—faunal abundance and its patchiness, faunal richness, and beta diversity—were examined at four contrasting dwarf-eelgrass localities in the Knysna estuarine bay, part of South Africa's Garden Route National Park but a system whose intertidal areas are heavily impacted anthropogenically. Faunal assemblages were significantly different across all localities and between subtidal and intertidal levels at each locality although their taxonomic distinctness was effectively constant. Although, as would be expected, there were clear trends for increases in overall numbers of species towards the mouth at all levels, few generalities relating to the relative importance of the subtidal seagrass habitat were evident across the whole system—magnitude and direction of differentials were contingent on locality. Shore-height related differences in assemblage metrics were minor in the estuarine and lagoonal zones but major in the marine compartment, although the much greater subtidal faunal abundance there was largely consequent on the superabundance of a single species (the microgastropod Alaba pinnae), intertidal zones then displaying the greater species diversity due to greater equitability of species densities. Along its axial channel, the Knysna subtidal seagrass does not support richer versions of the intertidal polychaete-dominated assemblages fringing it; instead, it supports different and more patchily dispersed gastropod-dominated ones. At Knysna at least, the subtidal hardly constitutes a reservoir of the seagrass biodiversity present intertidally.

Lure-assisted visual census: a new method for quantifying fish abundance, behaviour, and predation risk in shallow coastal habitats

2010 ◽  
Vol 61 (12) ◽  
pp. 1349 ◽  
Author(s):  
Claudia Kruschel ◽  
Stewart Schultz
Keyword(s):  
Predation Risk ◽  
Structural Complexity ◽  
Marine Ecology ◽  
Fish Abundance ◽  
Coastal Habitats ◽  
Field Methods ◽  
Bare Sediment ◽  
Faunal Abundance ◽  
Abundance And Diversity ◽  
Ambush Predators

Understanding the causes of variation in faunal abundance and diversity across shallow coastal habitats is a fundamental goal of marine ecology. Field methods for inferring a habitat effect on population density and predation risk are informative only if method biases are equal across habitats and species. We hypothesised that observation of fixed lures has a species by bias interaction if sampled species have different modes of predation, and that these biases are overcome by use of moving lures. We tested this hypothesis by observation of fixed and moving lures within seagrass and bare sediment in the Novigrad Sea, Croatian Adriatic. Both methods showed that ambush predators peaked in seagrass, wait–chasers peaked over bare sediment, and move–chasers were abundant in both. Stationary lures underestimated wait–chase and wait–ambush predators relative to moving lures, whereas moving lures did not underestimate the density of predators. These results indicate that stationary lures can underestimate both fish abundance and predation risk in the presence of waiting predators, and that if waiting predators are more abundant in structured habitat, then stationary lures will underestimate the predation risk within such habitats. Use of moving lures may be preferable for comparing habitats differing in structural complexity and frequency of predation modes.

Influences of natural acidity and introduced fish on faunal assemblages in California alpine lakes

1998 ◽  
Vol 55 (11) ◽  
pp. 2478-2491 ◽  
Author(s):  
David F Bradford ◽  
Scott D Cooper ◽  
Thomas M Jenkins, Jr. ◽  
Kim Kratz ◽  
Orlando Sarnelle ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
Taxon Richness ◽  
Introduced Fish ◽  
Faunal Assemblages ◽  
Acidic Lakes ◽  
Introduced Fishes ◽  
Daphnia Middendorffiana ◽  
Decreasing Ph ◽  
Natural Acidity ◽  
Macroinvertebrate Species

In an alpine area of the Sierra Nevada of California, naturally acidic waters and introduced fishes both strongly affect the distributions of native amphibians, zooplankton, and macroinvertebrates. The study area in Kings Canyon National Park contains 104 lakes with pH values between 5.0 and 9.3, including 10 lakes with pH < 6.0 (defined here as acidic lakes) and 18 lakes with introduced trout. We surveyed 33 of these lakes (8 acidic, 7 non-acidic with trout, 18 non-acidic without trout) for water chemistry and faunal assemblages. Yellow-legged frog tadpoles (Rana muscosa), common microcrustaceans (Daphnia, Hesperodiaptomus, Diaptomus), and larvae of a caddisfly (Hesperophylax) were rare or absent in acidic lakes but common in non-acidic lakes, and microcrustacean and macroinvertebrate species richness decreased with decreasing pH. Large and (or) mobile, conspicuous taxa, including tadpoles, large-bodied microcrustaceans (Hesperodiaptomus, Daphnia middendorffiana), and many epibenthic or limnetic macroinvertebrates (baetid and siphlonurid mayfly nymphs, notonectids, corixids, limnephilid caddis larvae, and dytiscid beetles), were rare or absent in trout lakes but were relatively common in lakes lacking trout, and the taxon richness of macroinvertebrates was reduced by trout.

The community associated with biogenic reefs formed by the polychaete, Serpula vermicularis

2011 ◽  
Vol 92 (4) ◽  
pp. 679-685 ◽  
Author(s):  
Nicola D. Chapman ◽  
Colin G. Moore ◽  
Dan B. Harries ◽  
Alastair. R. Lyndon
Keyword(s):  
Size Range ◽  
Taxon Richness ◽  
Reef Habitat ◽  
Modiolus Modiolus ◽  
Faunal Abundance ◽  
Special Area ◽  
Diverse Community ◽  
High Degree ◽  
Horse Mussel ◽  
Degree Of Similarity

The study aims to provide the first detailed account of the diversity and composition of the community associated with biogenic reefs formed by serpulid worms. Ten reefs (aggregations of calcareous Serpula vermicularis tubes), spanning a broad size-range, were collected from Loch Creran, Scotland, a Special Area of Conservation designated principally for the protection of its biogenic reefs. Total faunal abundance was strongly linearly related to reef weight, whilst taxon richness exhibited a hyperbolic relationship with reef size. 278 taxa were recorded from the ten reefs, with a reef of 0.1 m2 area supporting 163 taxa and 12756 individuals, which appears to represent considerable augmentation of diversity and abundance for sedimentary areas of the loch where the reefs occur. The reef assemblage was dominated by polychaetes (94 taxa), molluscs (70 taxa) and crustaceans (45 taxa). Species composition varied with reef size, although reefs greater than 25 cm width exhibited relatively little variation. In comparison with other biogenic polychaete habitats, S. vermicularis reefs appear to support a highly diverse community, which exhibits a high degree of similarity with that found in association with aggregations of the horse mussel, Modiolus modiolus. The presence of the Connemara clingfish, Lepadogaster candollei, rarely recorded at such a northerly latitude, on several reefs, indicates that the reef habitat may provide a stronghold for this species at the edge of its biogeographical range.

scholarly journals Effects of frond length on diverse gastropod assemblages in coralline turf

2003 ◽  
Vol 83 (1) ◽  
pp. 159-163 ◽  
Author(s):  
Brendan P. Kelaher
Keyword(s):  
Habitat Structure ◽  
Rocky Shore ◽  
Negative Relationship ◽  
Total Abundance ◽  
Faunal Assemblages ◽  
Vertical Scale ◽  
Abundance And Diversity ◽  
Frond Length ◽  
Sydney Australia

Habitat mimics were used to investigate the role of coralline algal frond length in determining spatial patterns in diverse gastropod assemblages on a rocky shore near Sydney, Australia. Frond length represents the vertical scale component of habitat structure, which is rarely experimentally manipulated. Length of fronds did not explain differences between gastropod assemblages at different tidal heights or among patches of turf separated by tens of metres in mid-shore areas. In contrast, changes in frond length caused large differences in the structure of gastropod assemblages in low-shore areas. Contrary to previous studies, the total abundance and diversity of gastropods was greater in turf with short fronds than with long fronds. Possible mechanisms for this negative relationship are discussed. Overall, the vertical scale component of habitat structure can have strong effects on associated faunal assemblages, but the magnitude of these effects depend heavily on local environmental conditions (e.g. different tidal heights).

Effects of wave exposure on the abundance and composition of amphipod and tanaidacean assemblages inhabiting intertidal coralline algae

2015 ◽  
pp. 1-7 ◽  
Author(s):  
M. Bueno ◽  
S.A. Dena-Silva ◽  
A.A.V. Flores ◽  
F.P.P. Leite
Keyword(s):  
Oxygen Concentration ◽  
Habitat Complexity ◽  
Wave Exposure ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Biological Interactions ◽  
Species Identity ◽  
Faunal Assemblages ◽  
Eastern Brazil ◽  
Different Levels

Peracarid crustaceans are an important component of the vagile fauna associated with coralline algal beds, which often characterize the infralittoral fringe of tropical rocky shores. Among other variables affecting faunal assemblages, sedimentation, food supply and oxygen concentration within mats or turfs of coralline algae may greatly depend on the exposure to waves. In this study, peracarid assemblages were compared at replicated rocky shores within different levels of wave exposure, along a coastline in south-eastern Brazil. Overall amphipod diversity (11 species) was much higher than tanaidacean diversity (two species). Correlation analyses did not support any biological interactions between amphipods and tanaidaceans. Habitat complexity, while apparently limiting amphipod populations, did not affect tanaidaceans at a local scale. Amphipod abundance, not assemblage structure, was positively affected by wave exposure, probably improving oxygen concentration levels and renewal of food resources. Rather than abundance, which remains fairly stable, exposure to waves determined species identity in tanaidaceans, withZeuxo coralensisfound at exposed shores andLeptocheliaaff.dubiafound at sheltered shores, except for twoL.aff.dubiaindividuals found at one of the exposed sites. Differences in the supply of sediment and the ability of these species in manipulating grains for tube building may explain such a striking pattern.

Advantages of zinc isotopes as a new dietary proxy in marine ecology

2020 ◽  
Author(s):  
Jeremy McCormack ◽  
Paul Szpak ◽  
Nicolas Bourgon ◽  
Michael P. Richards ◽  
Corrie Hyland ◽  
...  
Keyword(s):  
Trophic Level ◽  
Nitrogen Isotopes ◽  
Geographic Area ◽  
Marine Ecology ◽  
Trophic Levels ◽  
Dietary Analysis ◽  
Regional Food ◽  
Zinc Isotopes ◽  
Faunal Assemblages ◽  
Discrimination Factors

Abstract In marine ecology, dietary interpretations of faunal assemblages often rely on nitrogen isotopes as the main or only applicable trophic level tracer. We investigate geographic variability and trophic level isotopic discrimination factors of a new tracer, bone 66Zn/64Zn ratios (δ66Zn value), and compared it to collagen nitrogen and carbon stable isotope (δ15N and δ13C) values. Focusing on ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from multiple Arctic archaeological sites, we investigate trophic interactions between predator and prey over a broad geographic area. All proxies show variability among sites, influenced by the regional food web baselines. However, δ66Zn shows a significantly higher homogeneity among different sites. We observe a clear trophic spacing for δ15N and δ66Zn values in all locations, yet δ66Zn may more reliably record trophic levels between U. maritimus and prey species than δ15N. δ66Zn analysis allows a more direct dietary comparability between spatially and temporally distinct locations than what is possible by δ15N and δ13C analysis alone. When combining all three proxies a more detailed and refined dietary analysis is possible.

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