Influence of local-scale and landscape-scale habitat characteristics on California spiny lobster (Panulirus interruptus) abundance and survival

2007 ◽  
Vol 58 (5) ◽  
pp. 419 ◽  
Author(s):  
Thien T. Mai ◽  
Kevin A. Hovel
Keyword(s):  
Habitat Use ◽  
Habitat Structure ◽  
Spiny Lobster ◽  
Kelp Forest ◽  
Relative Survival ◽  
Landscape Scale ◽  
Habitat Characteristics ◽  
Ecological Processes ◽  
Panulirus Interruptus ◽  
Landscape Scales

For many marine systems, little is known about the effects of habitat structure on ecological processes that dictate population dynamics. This study focused on the effects of habitat structure on behaviour, abundance, and survival of California spiny lobster (Panulirus interruptus Randall) in the Point Loma kelp forest, San Diego, California. Habitat characteristics were quantified in 400-m2 landscapes to determine the role of shelter and understorey kelp characteristics at local (shelter) scales and landscape scales on lobster habitat use. A tethering experiment determined the effects of the presence of understorey kelp on lobster survival. At the shelter scale, lobsters preferred permanent shelters to ephemeral shelters, but did not respond to shelter size. At the landscape scale, lobster density increased with Pterygophora californica (stipitate kelp) density and decreased with Laminaria farlowii (prostrate kelp) density, but lobster density did not vary with shelter density or dispersion. Lobster size increased with P. californica density in two of three surveys, while lobster size did not vary with L. farlowii density. Lobster relative survival was higher in the presence of understorey kelp than when kelp was absent. We conclude that lobsters respond to habitat characteristics at local and landscape scales, and that understorey kelp has strong effects on lobster habitat use and survival.

Patterns of shelter use and their effects on the relative survival of subadult California spiny lobster (Panulirus interruptus)

2016 ◽  
Vol 67 (8) ◽  
pp. 1153 ◽  
Author(s):  
Amalia M. Harrington ◽  
Kevin A. Hovel
Keyword(s):  
Predation Risk ◽  
Field Experiments ◽  
Spiny Lobster ◽  
Relative Survival ◽  
Panulirus Interruptus ◽  
Rocky Reefs ◽  
Comprehensive Examination ◽  
Spiny Lobsters ◽  
Shelter Selection ◽  
Natural Reefs

Spiny lobsters use refuge habitat and gregarious behaviour to reduce predation risk, particularly in their vulnerable juvenile and subadult stages. We characterised patterns of sheltering behaviour in the California spiny lobster (Panulirus interruptus (Randall)) on southern California rocky reefs and used manipulative experiments to examine how these behaviours affect the survival of subadult lobsters and shelter selection. Lobsters generally were gregarious and subadults were commonly found inhabiting shelters with adult lobsters. Tethering experiments with subadults indicated that communal denning increases the odds of survival only when adult lobsters are part of aggregations. This corresponded to results from a shelter choice experiment in the laboratory, where the presence of predators caused subadults to shelter more often with adult conspecifics rather than other subadults. Despite the gregarious nature of P. interruptus, solitary subadults were common at all sites. Although field experiments clearly indicated that solitary lobsters increased their odds of survival by inhabiting shelters scaled to body size, evidence that lobsters exhibit shelter scaling on natural reefs was mixed. Our results indicate that subadult P. interruptus exhibit similar behavioural strategies as other spiny lobsters to reduce predation risk, and they provide a more comprehensive examination of P. interruptus behaviour than previously available.

scholarly journals Predator-induced selection on urchin activity level depends on urchin body size

2019 ◽  
Author(s):  
Justin Pretorius ◽  
James L.L. Lichtenstein ◽  
Erika J. Eliason ◽  
Adrian C. Stier ◽  
Jonathan N. Pruitt
Keyword(s):  
Body Size ◽  
Sea Urchins ◽  
Spiny Lobster ◽  
Activity Level ◽  
Kelp Forests ◽  
Ecological Processes ◽  
Panulirus Interruptus ◽  
Negative Effect ◽  
Slow Moving ◽  
The Stability

ABSTRACTTemporally consistent individual differences in behavior impact many ecological processes. We simultaneously examined the effects of individual variation in prey activity level, covering behavior, and body size on prey survival with predators using an urchin-lobster system. Specifically, we tested the hypothesis that slow-moving purple sea urchins (Strongylocentrotus purpuratus) and urchins who deploy extensive substrate (pebbles and stones) covering behavior will out-survive active urchins that deploy little to no covering behavior when pitted against a predator, the California spiny lobster (Panulirus interruptus). We evaluated this hypothesis by first confirming whether individual urchins exhibit temporally consistent differences in activity level and covering behavior, which they did. Next, we placed groups of four urchins in mesocosms with single lobster and monitored urchin survival for 108 hours. High activity level was negatively associated with survival, whereas urchin size and covering behavior independently did not influence survival. The negative effect of urchin activity level on urchin survival was strong for smaller urchins and weaker for large urchins. Taken together, these results suggest that purple urchin activity level and size jointly determine their susceptibility to predation by lobsters. This is potentially of great interest, because predation by recovering lobster populations could alter the stability of kelp forests by culling specific phenotypes, like foraging phenotypes, from urchin populations.

scholarly journals Valuation of kelp forest ecosystem services in the Falkland Islands: A case study integrating blue carbon sequestration potential

One Ecosystem ◽  
2021 ◽  
Vol 6 ◽  
Author(s):  
Daniel Bayley ◽  
Paul Brickle ◽  
Paul Brewin ◽  
Neil Golding ◽  
Tara Pelembe
Keyword(s):  
Ecosystem Services ◽  
Kelp Forest ◽  
Blue Carbon ◽  
Falkland Islands ◽  
Kelp Forests ◽  
Storm Damage ◽  
Ecological Processes ◽  
True Value ◽  
Sequestration Potential

Kelp forests provide many important ecosystem services to people, including mitigating storm damage, cycling nutrients, and providing commercially-harvestable resources. However, kelp forests’ ability to sequester carbon dioxide, and therefore help regulate the climate, has until recently, been overlooked in assessments of the beneficial services they provide. In this study we incorporate updated knowledge on the potential of kelp to sequester ‘blue carbon’, and use the extensive kelp forests of the Falkland Islands as a case study to assess the value of kelp forest to society through multiple associated ecosystem services. Our analysis shows kelp forests provide a highly valuable range of direct and indirect services, which if managed correctly, will continue to benefit people, both now and in the future. The total estimated value of the Falkland Islands’ kelp system is currently equivalent to ~ £2.69 billion per year (or £3.24 million km-2 year-1). However, the true value of the kelp forest surrounding the Falkland Islands is likely to be higher still, given that our estimate does not account for elements such as associated scientific research, tourism, and cultural services, due to the necessary data currently being unavailable. Similarly, the full value of these highly biodiverse ecosystems in supplying habitat and food to a large range of associated species is crucial, yet extremely difficult to fully quantify. This study illustrates the importance of maintaining kelp ecosystems in a healthy state to ensure they continue to supply valuable ecological processes, functional roles, and ecosystem services, including their overlooked role as significant long-term carbon sinks.

Fish Habitat: Essential Fish Habitat and Rehabilitation

1999 ◽  
Keyword(s):  
Field Experiment ◽  
Fish Habitat ◽  
Spiny Lobster ◽  
Basic Research ◽  
Florida Keys ◽  
Ecological Processes ◽  
Juvenile Recruitment ◽  
Before And After ◽  
Individual Survival ◽  
Concrete Blocks

<em>Abstract</em> .—Basic research on the settlement and postsettlement ecology of spiny lobster <em>Panulirus argus </em> has led to an application with the potential to replace lost natural refuge with artificial shelters intended for the vulnerable small juvenile stages. We began investigating ecological processes regulating juvenile spiny lobster recruitment in the Florida nursery in the mid-1980s. An unprecedented massive die-off of sponges in the middle Florida Keys followed cyanobacterial blooms in 1991–1993, ultimately affecting about 300 km2 of a region providing approximately one-fifth of total juvenile recruitment. Before 1991, crevices in sponges provided diurnal refuge from predators for about 70% of juveniles <50 mm carapace length. On the basis of sampling done before and after sponge loss, we estimated that juvenile abundance declined by 30–50% on spongeless sites without alternative shelter, resulting in a decrease of annual nurserywide potential of up to 10%. Results of a field experiment evaluating the relative influences of the magnitude of settlement and availability of crevice shelter on juvenile recruitment, fortuitously begun before the sponge die-off, showed that juvenile survival and abundance were sustained on small 0.02- to 0.07-ha test sites provided with supplemental artificial shelters (slotted concrete blocks). In the absence of sponges, survival of microwire-tagged juveniles on the shelter-supplemented sites was about six times higher than that on unsupplemented sites. On the basis of our earlier ecological findings, we devised a feasibility study to test whether the artificial shelters could replace lost sponge shelter for juvenile lobsters on a large scale. It took the form of a field experiment using 240 shelters spread over 1-ha sites located amid hard substrate denuded of sponges. The shelters provided substitute crevices, supporting juvenile lobster recruitment approximating that in areas with good sponge cover. This outcome exemplifies the essential value of initial basic research that provides understanding of the ecological processes regulating individual survival and, ultimately, the character and dynamics of the fishery population. Such an approach, and the information it provides, is necessary to successful rehabilitation of essential habitat or restocking of natural populations. Moreover, conducting basic research can help prevent the waste of precious time, funds, income, and human effort that typically has occurred in past failed attempts that were undertaken with insufficient knowledge. We urge the fisheries-ecology discipline and support agencies to promote strongly the primacy of research on basic processes.

Strategies for Restoring River Ecosystems: Sources of Variability and Uncertainty in Natural and Managed Systems

2003 ◽  
Keyword(s):  
Land Uses ◽  
Ecological Processes ◽  
Human Actions ◽  
Ecosystem Integrity ◽  
River Ecosystems ◽  
Natural Processes ◽  
Societal Needs ◽  
Hydrologic Regimes ◽  
Restoration Strategies ◽  
Landscape Scales

<em>Abstract</em>.—River ecosystem integrity is evaluated within a variety of landscape scales. We examine influences of variations in natural processes and human actions on river ecosystems and propose a concept for restoring impaired systems. The ecological structure and function of rivers vary across a hierarchy of landscape scales with different spatial and temporal dimensions. The major linkages within river systems include exchange of water and materials along longitudinal connections from streams to rivers, lateral connections between river and floodplain systems, and vertical surface and subsurface (hyporheic) water exchanges. Strong longitudinal linkages dominate confined river reaches while unconfined floodplain reaches show strong affinities for lateral and vertical exchange. A landscape concept, “the shifting habitat mosaic” (SHM), provides a framework for understanding how these interactions create and maintain the physical and ecological diversity of habitats, biotic communities, and ecosystem integrity. While each river system has unique physical and ecological characteristics, many human actions and ecological effects can be expressed within the SHM concept. For example, societal needs for power generation, transportation, water management, and land uses (e.g., urban and agricultural) often alter natural processes of hydrologic regimes and material transport and deposition. These factors affect interactions between the river channel and the surrounding river–riparian corridor. Restoration strategies can apply the SHM concept by focusing on restoring normative variations to processes (e.g., hydrologic regimes) that contribute to ecosystem integrity. Management practices (e.g., dam hydrologic regimes, flood control facilities, levees, land uses) can be modified to restore natural physical and ecological processes (e.g., thermal regimes, water exchange, and animal migrations).

Effects of a Transmission Line on Bird Populations in the Red Lake Peatland, Northern Minnesota

The Auk ◽  
1984 ◽  
Vol 101 (3) ◽  
pp. 487-498 ◽  
Author(s):  
Gerald J. Niemi ◽  
JoAnn M. Hanowski
Keyword(s):  
Transmission Line ◽  
Habitat Structure ◽  
Breeding Population ◽  
Habitat Characteristics ◽  
Population Densities ◽  
Yearly Variation ◽  
Bird Populations ◽  
Census Methods ◽  
Habitat Differences ◽  
Transect Counts

Abstract The effects of a 500-kV transmission line on bird populations were assessed by comparing paired treatment areas [which included a transmission line and right-of-way (ROW)] with similar control areas in six different habitat types during the breeding and migration seasons. Habitat structure was measured to examine the inherent differences between control and treatment areas. Using two census methods, territorial mapping and transect counts, we determined that Sedge Wrens and LeConte's Sparrows had lower breeding-population densities in treatment areas than in control areas. LeConte's Sparrows and Connecticut Warblers occurred at greater mean distances from the transmission line in treatment areas than from a similarly positioned line in control areas. Fifteen paired t-tests (five habitats in 3 yr), in which territorial mapping data were used, revealed that community densities were lower in one treatment habitat (high shrub) in 1 of 3 yr (P < 0.05). A two-way analysis of variance with transect counts, however, was not confirmatory when yearly variation was included. Transect counts revealed lower population densities in one treatment habitat (low shrub) in 2 of 3 yr (P < 0.05). In contrast, we observed greater species richness (P < 0.05) in two treatment habitats (closed spruce and sedge fen) than in controls. Treatment habitats were most similar in habitat structure to their paired control habitats, but each habitat of the pair was significantly different (P < 0.05) from the other in at least 2 of 10 habitat characteristics analyzed. We suggest that the avian differences observed between paired areas were primarily attributable to (1) the inherent habitat differences between control and treatment areas, and (2) the new habitat created under the transmission line. Our data indicated negligible effects of this transmission line on bird populations, but interpretations are difficult, because the effects varied with (1) habitat, (2) season, and (3) method considered. Postimpact studies, which compare control and treatment areas, are less effective than before-and-after studies, because differences in habitat structure exist between any two areas.

scholarly journals Linking ecology and cognition: does ecological specialisation predict cognitive test performance?

2020 ◽  
Vol 74 (12) ◽  
Author(s):  
Johanna Henke-von der Malsburg ◽  
Peter M. Kappeler ◽  
Claudia Fichtel
Keyword(s):  
Cognitive Performance ◽  
Test Performance ◽  
Cognitive Abilities ◽  
Social Intelligence ◽  
Brain Size ◽  
Relevant Literature ◽  
Interspecific Variation ◽  
Habitat Characteristics ◽  
Cognitive Test ◽  
Ecological Processes

AbstractVariation in cognitive abilities is thought to be linked to variation in brain size, which varies across species with either social factors (Social Intelligence Hypothesis) or ecological challenges (Ecological Intelligence Hypothesis). However, the nature of the ecological processes invoked by the Ecological Intelligence Hypothesis, like adaptations to certain habitat characteristics or dietary requirements, remains relatively poorly known. Here, we review comparative studies that experimentally investigated interspecific variation in cognitive performance in relation to a species’ degree of ecological specialisation. Overall, the relevant literature was biased towards studies of mammals and birds as well as studies focusing on ecological challenges related to diet. We separated ecological challenges into those related to searching for food, accessing a food item and memorising food locations. We found interspecific variation in cognitive performance that can be explained by adaptations to different foraging styles. Species-specific adaptations to certain ecological conditions, like food patch distribution, characteristics of food items or seasonality also broadly predicted variation in cognitive abilities. A species’ innovative problem-solving and spatial processing ability, for example, could be explained by its use of specific foraging techniques or search strategies, respectively. Further, habitat generalists were more likely to outperform habitat specialists. Hence, we found evidence that ecological adaptations and cognitive performance are linked and that the classification concept of ecological specialisation can explain variation in cognitive performance only with regard to habitat, but not dietary specialisation.

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