scholarly journals Spatial, temporal and ontogenetic variation in the association of fishes (family Labridae) with rocky-reef habitats

2011 ◽  
Vol 62 (7) ◽  
pp. 870 ◽  
Author(s):  
Jason K. Morton ◽  
William Gladstone
Keyword(s):  
Fish Assemblages ◽  
Spatial Scales ◽  
Abundant Species ◽  
Habitat Associations ◽  
Rocky Reef ◽  
Habitat Variability ◽  
Life History Stages ◽  
Multiple Spatial Scales ◽  
Habitat Specialisation ◽  
Rocky Reefs

Habitat variability is an important factor structuring fish assemblages of rocky reefs in temperate Australia. Accepting the generality of this model requires that habitat-related variation is consistent through time, across multiple spatial scales, and applies to all life-history stages. We used repeated underwater visual surveys at multiple spatial scales over a 22-month period to test whether three distinct rocky-reef habitats had different wrasse assemblages and whether these assemblages were subject to spatial, temporal and ontogenetic variability. Overall, the strongest and most consistent habitat association was with sponge gardens, which had the most distinct assemblage, and the greatest species richness and density of individuals. Habitat associations in fringe and barrens were less consistent. A substantial increase in the abundance of small individuals, coinciding with warmer sea temperatures, contributed to temporal fluctuations in the density of wrasses. Overall, habitats were not strongly partitioned among larger individuals of the most abundant species, suggesting that adults are largely habitat generalists whereas small, recruiting individuals showed greater habitat specialisation. The present study emphasises the importance of incorporating spatial, temporal and ontogenetic variability into surveys of fish assemblages to understand more fully the dynamics of temperate rocky-reef systems.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

2018 ◽  
Keyword(s):  
Spatial Scales ◽  
Artificial Reef ◽  
Volume Ratio ◽  
Primary Objective ◽  
Rocky Reef ◽  
Reef Habitat ◽  
The Past ◽  
Multiple Spatial Scales ◽  
Subtidal Rocky Reefs ◽  
Natural Reefs

<em>Abstract</em>.—The subtidal rocky reefs that surround the Palos Verdes Peninsula in Los Angeles County, California, USA are subject to multiple anthropogenic impacts, including many (at least partially) human-induced landslides over the past half century, which have resulted in chronic sedimentation (e.g., reef burial and scour) and associated turbidity effects along a major stretch of this coastline. The amount of rocky reef habitat has significantly decreased; as such, determining the optimum technique for restoring this lost habitat is the focus of this study. Over the past decade, we mapped and intensively surveyed the nearshore physical and biological characteristics both inside this impacted area and in surrounding reference areas that contain extensive rocky reef habitat with established kelp forests. Notable among all survey locations is a relatively high-relief (~5 m) area of reef within the sediment impacted area that consistently has the highest fish biomass density among anywhere on the peninsula. The high structural relief prevents sediment accumulation, scour, and subsequent reef burial, and this reef ultimately served as the example for the design of sets of quarry rock reef “blocks” that together form the proposed restoration reef. Our primary objective was to use the 63,500 metric tons of quarry rock the budget would allow us to create the most productive habitat by restoring the natural reef environment while balancing scientific study design considerations (i.e., replicated reef components at multiple spatial scales) with maximizing the potential for an effective restoration effort across the range of important species and overall kelp forest biodiversity. To meet this objective, we considered multiple criteria that incorporated engineering specifications and biological performance and were informed by the scientific literature and results of natural and artificial reef surveys in this region. Ultimately, the design incorporated heterogeneity at multiple spatial scales while attempting to maximize high relief components, surface area to volume ratio, perimeter, ecotones, and small-scale current flow features and nutrient flux and while being consistent with the size of natural reefs along the Palos Verdes Peninsula. Further, placement and spacing of individual reef blocks (i.e., 2 × 48 m heterogeneous quarry rock reefs) included space for sand channels between blocks to permit sediment transport and create sand/rock ecotone habitats while remaining close enough to each other and existing natural reefs to maintain biological connectivity. Reef blocks were also located at the depth (15–20 m) where the most productive reef habitat in the region was observed. Finally, we discuss a proposed pre- and post-construction monitoring program and additional studies that could be performed that would leverage the replicated elements in the restoration reef design to inform future reef restoration programs.

Scrub–Shrub Bird Habitat Associations at Multiple Spatial Scales in Beaver Meadows in Massachusetts

The Auk ◽  
2009 ◽  
Vol 126 (1) ◽  
pp. 186-197 ◽  
Author(s):  
Richard B. Chandler ◽  
David I. King ◽  
Stephen Destefano
Keyword(s):  
Spatial Scales ◽  
Habitat Associations ◽  
Multiple Spatial Scales ◽  
Bird Habitat

Spatiotemporal variation in the structure of reef fish and macroalgal assemblages in a north-east Atlantic kelp forest ecosystem: implications for the management of temperate rocky reefs

2018 ◽  
Vol 69 (4) ◽  
pp. 525 ◽  
Author(s):  
Pablo Pita ◽  
Diana Fernández-Márquez ◽  
Juan Freire
Keyword(s):  
Reef Fish ◽  
Fish Assemblages ◽  
Kelp Forest ◽  
Habitat Destruction ◽  
Kelp Forests ◽  
Rocky Reef ◽  
Laminaria Hyperborea ◽  
East Atlantic ◽  
North East ◽  
Rocky Reefs

Temperate rocky reefs and kelp forest ecosystems have been severely affected by overfishing, pollution and habitat destruction, and climate change is a major driver of kelp decline in many regions. Although necessary for management, ecological interactions between kelp and fish remain largely unknown in the north-east Atlantic. In the present study, underwater visual censuses (UVC) and univariate and multivariate multiple regression models were used to analyse the spatiotemporal variations in the abundance and habitat use of the rocky reef fish and macroalgae assemblages of Galicia (north-west Spain). The underwater seascape was dominated by large rocks and kelp forests of Laminaria hyperborea, L. ochroleuca and Saccorhiza polyschides. Fish assemblages were ruled by gadids, labrids and sparids. The most frequent fish species were Labrus bergylta (counted in 90% of UVC) and Pollachius pollachius (in 100% of UVC), whereas the most abundant were Boops boops (mean±s.d., 556.4±39.7 individuals ha–1) and L. bergylta (432.10±440.05 individuals ha–1). Fish and macroalgal assemblages showed different spatial preferences and responded strongly to seasonality, wave exposure and depth. To a lesser degree, fish and macroalgal assemblages showed preferences for habitat structure. Moreover, because the findings of the present study indicate that L. bergylta is a good indicator species of the health of rocky reef and kelp forests ecosystems, monitoring of this fish can be helpful for management and conservation actions.

Movements and distribution of dugongs (Dugong dugon) in a macro-tidal environment in northern Australia

2008 ◽  
Vol 56 (4) ◽  
pp. 215 ◽  
Author(s):  
Scott D. Whiting
Keyword(s):  
Spatial Scales ◽  
Close Association ◽  
Information Source ◽  
Satellite Tracking ◽  
Rocky Reef ◽  
Rocky Reefs ◽  
Aerial Surveys ◽  
Satellite Transmitters ◽  
Spatial Use ◽  
Four Blocks

A combination of aerial surveys, community sightings and satellite tracking revealed distribution, habitat, relative densities and spatial use of individual dugongs in the Darwin region of the Northern Territory. Aerial surveys in both the wet and dry seasons estimated relatively low densities of dugongs. Most group sightings (73% of all sightings) and densities up to 0.54 dugongs km−2 occurred in one of the four blocks surveyed. This block contained the Vernon Islands and large macro-tidal algal rocky reefs. Two dugongs tracked using satellite transmitters were captured above these reefs and kept a close association with similar reef types during most of their tracking periods of 53 and 154 days. Tracking revealed that dugongs used multiple and distinct areas for periods of several days to over 80 days and utilised coastal sections of up to 300 km in length. This indicates that dugong management in the Darwin region requires the consideration of large spatial scales, multiple habitat types and rocky reef habitat. Community sightings were an important information source and revealed locations of dugongs not identified with either the aerial surveys or satellite tracking.

Consequences of hydrological alteration for beta diversity of fish assemblages at multiple spatial scales

2021 ◽  
pp. 149170
Author(s):  
Robert J. Rolls ◽  
Bruce C. Chessman ◽  
Jani Heino ◽  
Ben Wolfenden ◽  
Ivor O. Growns ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Fish Assemblages ◽  
Spatial Scales ◽  
Multiple Spatial Scales ◽  
Hydrological Alteration

scholarly journals At what spatial scales are alternative stable states relevant in highly interconnected ecosystems?

2019 ◽  
Author(s):  
Vadim A. Karatayev ◽  
Marissa L. Baskett
Keyword(s):  
Spatial Scales ◽  
Alternative Stable States ◽  
Stable State ◽  
Environmental Stochasticity ◽  
Rocky Reef ◽  
Alternative States ◽  
Stable States ◽  
Long Distance ◽  
Rocky Reefs ◽  
Model Predictions

AbstractWhether ecosystems recover from disturbance depends on the presence of alternative stable states, which are theoretically possible in simple models of many systems. However, definitive empirical evidence for this phenomenon remains limited to demographically closed ecosystems such as lakes. In more interconnected systems such as temperate rocky reefs, the local relevance of alternative stable states might erode as immigration overwhelms local feedbacks and produces a single stable state. At larger spatial scales, dispersal might counter localized disturbance and feedbacks to synchronize states throughout a region. Here, we quantify how interconnectedness affects the relevance of alternative stable states using dynamical models of California rocky reef communities that incorporate observed environmental stochasticity and feedback loops in kelp-urchin-predator interactions. Our models demonstrate the potential for localized alternative states despite high interconnectedness likely due to feedbacks affecting dispersers as they settle into local communities. Regionally, such feedbacks affecting settlement can produce a mosaic of alternative stable states that span local (10-20km) scales despite the synchronizing effect of long-distance dispersal. The specific spatial scale and duration of each state predominantly depend on the scales of environmental variation and on local dynamics (here, fishing). Model predictions reflect observed scales of community states in California rocky reefs and suggest how alternative states co-occur in the wide array of marine and terrestrial systems with settlement feedbacks.

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