Small Marine Reserves Research Articles

High population density enhances recruitment and survival of a harvested coral reef fish

A negative relationship between population growth and population density (direct density dependence) is necessary for population regulation and is assumed in most models of harvested populations. Experimental tests for density dependence are lacking for large-bodied, harvested fish because of the difficulty of manipulating population density over large areas. We studied a harvested coral reef fish, Lutjanus apodus (schoolmaster snapper), using eight large, isolated natural reefs (0.4-1.6 ha) in the Bahamas as replicates. An initial observational test for density dependence was followed by a manipulation of population density. The manipulation weakened an association between density and shelter-providing habitat features and revealed a positive effect of population density on recruitment and survival (inverse density dependence), but no effect of density on somatic growth. The snappers on an individual reef were organized into a few shoals, and we hypothesize that large shoals on high-density reefs were less vulnerable to large piscivores (groupers and barracudas) than the small shoals on low-density reefs. Reductions in predation risk for individuals in large social groups are well documented, but because snapper shoals occupied reefs the size of small marine reserves, these ecological interactions may influence the outcome of management actions.

Commercial fishery effort for California spiny lobster (Panulirus interruptus) off Orange County, California before State Marine Reserve implementation

Abstract The California spiny lobster (Panulirus interruptus) commercial fishing effort along the southern Orange County, California coastline was examined using fishery-independent counts of trap marker buoys and fishery-dependent information submitted to the California Department of Fish and Game in the required commercial logbooks. Buoy counts were conducted in spatially-discrete subsections of the coastline inshore of the 30-m isobath to determine the density of fishing effort at a scale finer than is afforded by the standard fishing blocks used by the Department of Fish and Game. Both the buoy densities and fisherman-reported trap pull counts recorded declining effort across the area as the season progressed. Effort was more diffuse at the beginning of the season, but increasingly focused on areas covered by giant kelp canopy, including the boundary of a previously existing, small no-take marine reserve located in the study area. General effort declined as the frequency of capturing a harvestable Cal...

Small marine reserves can offer long term protection to an endangered fish

The protection of exploited species offered by marine reserves is maximised if individual fish live within the boundaries of the reserve for most of their lives. The direct benefit of this protection, the so called ‘reserve effect’, is the build-up of biomass through an increase in individual numbers and size. This effect can take several years depending on the life history traits of the target species. However, empirical studies on individual fish spatial behaviour at temporal scales long enough to be compatible with that of invoking the reserve effect are still virtually lacking. We studied the inter-annual patterns of habitat use of the dusky grouper ( Epinephelus marginatus), an endangered reef fish predator, using passive acoustic telemetry inside and around a small marine reserve in the Azores, mid-north Atlantic. All 11 individuals resided in the reserve year-round for up to 5 years. During these periods, fish were detected nearly every day and utilised stable core activity areas. Two smaller fish apparently abandoned the area after some time, probably relocating outside the reserve. Our results indicate that even small marine reserves can promote the long-term recovery of some endangered species if the long-term behaviour (i.e. site fidelity) of individuals is appropriate. This result bears direct implications for most existing coastal marine reserves, given that they fall into the small size range and many overexploited reef fish species may be highly site attached.

Effectiveness of a small marine reserve in southern China in protecting the harvested sea urchin Anthocidaris crassispina: A mark-and-recapture study

Assessment of the effectiveness of protected areas requires information on population characteristics of the target species. This study used a mark-and-recapture approach to examine the population structure, individual growth, and mortality of the commercially harvested short-spined sea urchin Anthocidaris crassispina in a small (18 ha) no-take marine reserve and two nearby non-protected sites. Sea urchins were tagged with fluorochrome and recaptured 1 year later. The size-at-age relationship was modelled using the Tanaka function, and mortality estimated using an exponential decay function coupled with the Tanaka growth parameters. The urchin population in the reserve consisted of a higher proportion of older individuals than populations in the two non-protected areas, however, large sea urchins (>50 mm) were absent in the reserve. Sea urchins occurring at high densities (>15 ind. m −2) in the reserve grew much slower than those outside the reserve, suggesting a density-dependant effect on growth. Growth ring analysis from the rotulae supported the mark-and-recapture results with the maximum number of rings being higher in the reserve than in non-protected sites. Urchins with the same number of growth rings inside the reserve were smaller than those outside the reserve. Within the reserve, urchins with the same number of growth rings were smaller at locations with higher urchin density. Annual mortality rate was lower in the reserve population than in the non-protected populations. These results illustrate the effectiveness of this small reserve in protecting A. crassispina from fishing. However, further study is required to examine whether a high density of small/old individuals is better than a medium density of large individuals in order to maximize the potential spillover of larvae by such small urchin refugia to the surrounding overfished areas.

Effectiveness of five small Philippines’ coral reef reserves for fish populations depends on site-specific factors, particularly enforcement history

Community-managed, no-take marine reserves are increasingly promoted as a simple, precautionary measure to conserve biodiversity and sustain coral reef fisheries. However, we need to demonstrate the effects of such reserves to those affected by the loss of potential fishing grounds and the wider scientific community. We surveyed changes in fish communities in five small marine reserves in the central Philippines and three distant Control sites over seven years. We conducted underwater visual censuses of 53 fish families within the reserve (Inside), with a kilometre of the boundary (Outside) and at Control sites. We found significant differences between fish communities Inside and Outside the reserve only at the two sites with strictest compliance with fishing prohibition, while there were significant differences to distant Control sites in all cases. The strongest responses to reserve protection were found in predatory fishes (groupers and breams) and in butterflyfish. Other abundant fish families showed weak effects of protection. For all taxa analysed, we found significant effects of reserve Site and Site × Treatment interactions. The detection of fish responses to reserves is complicated by potential spillover effects, site-specific factors, particularly compliance, and the difficulty of identifying appropriate control areas.

The impact of marine reserves on nekton diversity and community composition in subtropical eastern Australia

The effectiveness of marine reserve protection on the biodiversity of aquatic assemblages (i.e. nekton) in subtropical eastern Australia was examined within two small (<6 km 2) marine reserves and four non-reserve areas. The two marine reserves, and their corresponding non-reserves, were located in different geographical locations within Moreton Bay (north and south) and sites were surveyed with multiple hauls of a seine net. Species richness, evenness, density and mean size of the inshore communities were compared between the reserves and non-reserves. No statistical significant difference was detected in species richness between the areas however species evenness was significantly lower in the only non-reserve site impacted by commercial net fishing. Mean size of nekton was found to be significantly greater in the marine reserves compared to non-reserves but no statistical significant difference was found in the density of nekton between the study sites. Multivariate analysis revealed differences in community composition, particularly between the geographical locations where areas were impacted by different types of fishing pressure (recreational v commercial). These results highlight the impact commercial fishing can have on entire nekton assemblages, not just on targeted species. Our study demonstrates that the small marine reserves in Moreton Bay are protecting marine biodiversity and are thus at least partially achieving their management objective (to enhance the zone’s marine biodiversity).

The Fish Assemblages Inside and Outside of a Temperate Marine Reserve in Southern California

Abstract The purpose of this investigation was to evaluate the effect of a small marine reserve (established 1988) on a temperate rocky reef fish assemblage at Santa Catalina Island, California. Fish surveys on SCUBA were conducted at two reserve and two non-reserve sites from October 2002 to January 2004. Sites were similar in fish density, species richness and biomass of the entire fish assemblage. However, the adult densities of two important fishery species, California sheep-head (Semicossyphus pulcher; 7.6 ±0.5 and 5.5 ±0.4/100 m2 inside versus outside) and kelp bass (Paralabrax clathratus; 3.6 ±0.4 and 2.9 ±0.4 inside versus outside), were significantly higher within the reserve. The reserve appears to be effective in increasing density and biomass of two impacted species that were readily observed and surveyed on SCUBA.

Protection of the goose barnacle Pollicipes pollicipes, Gmelin, 1790 population: the Gaztelugatxe Marine Reserve (Basque Country, northern Spain)

Marine protected areas are expected to play a prominent role in the conservation of marine resources and fisheries management. In the Basque Country (northern Spain) the small Marine Reserve of Gaztelugatxe (158 ha) was established in 1998. One of the aspects taken into account in protecting this area was the overexploitation of the goose barnacle Pollicipes pollicipes. Now, after five years of protection, differences in density, biomass, size and weight of the goose barnacle are investigated inside the protected area (Aketze and Gaztelugatxe locations) and outside of it, at the nearest locations (Izaro and Ogono) which have been continuously exploited. This contribution demonstrates that the reserve could be an efficient tool in preserving the goose barnacle populations in the area. Hence, density, biomass and allometric coefficients are higher in the protected areas. These locations are also associated with higher percentages of juveniles, together with a high number of large-sized individuals.

Habitat Preferences and Site Fidelity of the Ornate Wobbegong Shark (Orectolobus ornatus) on Rocky Reefs of New South Wales

Habitat and microhabitat preferences and site fidelity of Orectolobus ornatus were assessed between September 2002 and August 2003 to assess potential suitability of marine reserves for its conservation. Of six rocky reef habitats available in the study area (sponge gardens, artificial structures, barren boulders, sand, sea grass, macroalgae), O. ornatus exhibited a significant preference for sponge gardens, artificial structures, and barren boulders habitats. Habitat preferences of males and females, and individuals 1 m, did not differ. Orectolobus ornatus selected daytime resting positions with a high topographic complexity and crevice volume and did not select on the basis of prey availability. Habitat and microhabitat preferences may be related to the need for predator avoidance. Regular monitoring of 40 individually identified O. ornatus revealed that none was a permanent resident of the study area. Seven individuals exhibited short-term temporary fidelity to the study area; they were resighted frequently for part of an intensive 100-day survey. Remaining individuals were temporary visitors; they were resighted at most once after initial identification or returning after extended absences. Monthly population surveys confirmed the turnover of O. ornatus in the study area. The lack of long-term site fidelity suggests that small marine reserves will be ineffective as a conservation strategy for O. ornatus.

Small-scale field experiments accurately scale up to predict density dependence in reef fish populations at large scales.

Field experiments provide rigorous tests of ecological hypotheses but are usually limited to small spatial scales. It is thus unclear whether these findings extrapolate to larger scales relevant to conservation and management. We show that the results of experiments detecting density-dependent mortality of reef fish on small habitat patches scale up to have similar effects on much larger entire reefs that are the size of small marine reserves and approach the scale at which some reef fisheries operate. We suggest that accurate scaling is due to the type of species interaction causing local density dependence and the fact that localized events can be aggregated to describe larger-scale interactions with minimal distortion. Careful extrapolation from small-scale experiments identifying species interactions and their effects should improve our ability to predict the outcomes of alternative management strategies for coral reef fishes and their habitats.

Effectiveness of a small marine reserve in southern California

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 296:39-52 (2005) - doi:10.3354/meps296039 Effectiveness of a small marine reserve in southern California P. Ed Parnell1, Cleridy E. Lennert-Cody2, Leen Geelen3, Laura D. Stanley4, Paul K. Dayton1 1Scripps Institution of Oceanography, Integrative Oceanography Division, University of California, San Diego, La Jolla, California 92093-0227, USA2Inter-American Tropical Tuna Commission, 8604 La Jolla Shores Drive, La Jolla, California 92037-1508, USA367 bis Rue du Point du Jour, 92100 Boulogne-Billancourt, France 4UCSD Civic Collaborative, University of California, San Diego, La Jolla, California 92093-0176P, USA *Email: edparnell@ucsd.edu ABSTRACT: While relatively small, the San Diego–La Jolla Ecological Reserve is one of the oldest in California, and it contains giant-kelp-forest, boulder-reef, submarine-canyon and sandy-shelf habitats. We evaluated the effectiveness of this ‘no-take’ marine reserve and gauged its success according to the goals implicit in its design. To overcome the lack of data prior to its establishment, we employed habitat-specific analyses. Our study comprised 4 components: (1) an historical review of its establishment; (2) a survey of conspicuous species in kelp-forest, submarine-canyon, and boulder-reef habitats; (3) comparisons with historical data; (4) a public survey regarding awareness, knowledge, and support of the reserve. Despite 30 yr of protection, only a few sessile or residential species exhibit positive effects of protection, and most fished species have decreased in abundance inside the reserve. However, the reserve protects the largest remaining populations of green abalone Haliotis fulgens and vermillion rockfish Sebastes miniatus in the area, which therefore represent important sources of larvae. Implementation and enforcement of coastal reserves depends on public support, but the results of the public survey indicated a lack of knowledge of the reserve, highlighting the need for improved public education in this respect. The results of the study reflect the limited value of small reserves and document the inadequacy of inside/outside comparisons as tests of reserve effectiveness when baseline and historical data are lacking. KEY WORDS: Marine protected area · Reserves · Kelp · Abalone · Urchins · Submarine-canyon · Rockfish · Public opinion Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 296. Online publication date: July 12, 2005 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2005 Inter-Research.

Species-specific impacts of a small marine reserve on reef fish production and fishing productivity in the Turks and Caicos Islands

Marine reserves are widely considered to potentially benefit reef fisheries through emigration, yet the empirical basis for predicting the extent of this for small reserves is weak. The effects of fishing pressure and habitat on biomass and catch per unit effort (CPUE) of three species of exploited reef fish were studied at South Caicos, Turks and Caicos Islands. Distribution and abundance of hogfish (Lachnolaimus maximus) and white margate (Haemulon album) were inversely correlated with cover of fleshy macroalgae. Nassau grouper (Epinephelus striatus) were positively associated with vertical relief, but were unaffected by algal cover. Mean size, density, and biomass of hogfish were higher in a small (4 km2) marine reserve than on fished reefs, as was biomass of white margate. CPUE of hogfish was inversely related to distance from the centre of the reserve, suggesting that spillover of this species from the reserve to adjacent reefs may enhance local yields, possibly providing economic incentives for fishers to comply with reserve regulations. Fishing pressure, however, had no apparent effect on Nassau grouper. Larger fishes and those that migrate to spawn, such as economically valuable Nassau grouper, may move over too large a range to be effectively protected by small marine reserves. Small reserves may not protect all fish, but they can increase the biomass of smaller or more sedentary reef fishes and may be a useful tool for the conservation or management of species such as hogfish. Other policy options, such as seasonal spawning closures or total allowable catches, need to be considered for larger, more mobile fishes in the Turks and Caicos Islands.

Small Marine Reserves May Increase Escapement of Red Drum

Abstract An experimental stock enhancement program was conducted in Port Royal Sound estuary, South Carolina, in which cultured juvenile red drum (Sciaenops ocellatus, 2–3 cm TL, ∼40 days old) were released into a system of shallow tidal creeks that flow into the Colleton River. All fish were immersed in oxytetracycline (OTC) prior to release to produce an identifiable, chemical mark on the otoliths. The release area was typical of primary nursery habitat in this region. For four years post-stocking, fish were collected throughout the sound using hook and line, spear, and trammel net. Otoliths were examined for OTC marks to determine which fish were of hatchery origin. It was found that while dispersal was substantial, many stocked fish stayed in the general area of release (1.8 × 3.2 km) until reaching the age of maturity (∼age 3) when they left the estuary, and at all ages they were mixed with wild fish. This suggests that relatively small areas containing the appropriate suite of habitat types could be...

Effects of Human Activity on the Structure of Coastal Marine Bird Assemblages in Central Chile

Abstract:In comparison with the effects of the collection of marine intertidal organisms by humans, the effects of human recreational activities on assemblages of marine birds have received scarce attention. We evaluated whether in central Chile the spatial and temporal variation in the composition and abundance of the avian assemblage is affected by the presence of humans on the coast. We studied a 1.5‐km stretch of rocky coast, in the center of which is a small marine reserve where no fishing or recreational activities take place. At 15 observation points, we conducted 12 monthly surveys of birds that roost in the supralittoral zone, between the high‐tide mark and the terrestrial vegetation, and/or that forage in the intertidal zone. In addition, within the reserve we conducted daily bird surveys over 2 years to evaluate whether abundance or composition changed according to the activity of people outside the reserve. We recorded 19 species of coastal marine birds. Eleven species used the supralittoral zone only for roosting (roosting assemblage), whereas the others foraged on intertidal organisms and roosted in the supralittoral zone ( foraging assemblage). Although the largest negative effect of human activity on bird abundance occurred in summer, the period of greatest recreation intensity, the presence of humans negatively affected birds year round, changing both the spatial and temporal distribution of birds along the shore. Bird abundance was higher at observation points inside the marine reserve, although the pattern was stronger for birds roosting on the supralittoral zone than for birds actively foraging in the intertidal zone. Similarly, the number of birds recorded during weekends inside the reserve was higher than during week days. Our results illustrate the important role played by this marine reserve, which offers marine birds safe roosting sites without human interference. Larger marine reserves than the one we studied are needed because the dynamics of birds inside the reserve were strongly influenced by human activities in immediately adjacent areas. Our results emphasize the need to consider human recreational activities along the coast when establishing conservation programs because harvesting refugia or “no‐take” zones will not provide protection to coastal bird assemblages unless human access is restricted.

Single large or several small marine reserves for the Caribbean spiny lobster?

The ‘SLOSS’ debate—Single Large Or Several Small protected areas—remains unresolved. We used a heuristic model based on population dynamics of Caribbean spiny lobster in Exuma Sound, Bahamas, to compare impacts of regional reserve designs that configured 20% of available coastal habitat as either a randomly located single large reserve or a network of six small, randomly located reserves on three performance indicators (fishery yield, larval production, population growth rate) for a hypothetical overexploited lobster population. Two additional management strategies were considered: one reduced effort by 20% (without protected areas), and one did nothing. Effects were evaluated for two levels of hydrodynamic variability. In general, performance indicators ranked the management strategies, independent of hydrodynamic variability, from best to worst in the order (1) single large reserve (2) several small reserves (3) reduced effort (4) no management action, but differences were not always significant. Therefore, for the model regional system investigated here, a single large reserve is preferable to several small ones. We propose that this conservation strategy is most suitable at the regional scale (~100s of kilometres) and that such single, large regional reserves would function most effectively within a broadscale (~1000s of kilometres) reserve network, barring local catastrophes.

Movement Patterns, Habitat Utilization, Home Range Size and Site Fidelity of Whitesaddle Goatfish, Parupeneus Porphyreus, In a Marine Reserve

Suitability of small (< 1 km2) marine reserves for protecting a commercially important endemic Hawaiian goatfish, Parupeneus porphyreus, was examined by quantifying goatfish habitat use, home range size and site fidelity in an existing marine reserve (Coconut Island in Kaneohe Bay, Hawaii). Five goatfish equipped with acoustic transmitters were tracked for up to 93 h each over 3–14 days. Daytime habitat use patterns of two of these fish were continuously monitored for one month using a fixed hydrophone hardwired to an onshore computer. Acoustically tagged fish showed consistent diel patterns of behavior, refuging in holes in the reef by day and moving over extensive areas of sand and coral rubble habitat at night. Remote monitoring of daytime habitat use by two goatfish revealed that the same daytime refuge was used by both fish for at least one month (the battery life of the transmitters). Home ranges of all fish were within the boundaries of the Coconut Island reserve suggesting that even small areas containing suitable habitat can make effective reserves for this species. A relatively low abundance of reproductive size P. porphyreus at Coconut Island in comparison with deeper areas may indicate an ontogenetic shift to deeper habitat in this species.

Marine protected areas and local coastal conservation and management in Hong Kong

This paper focuses on the role of marine parks and reserves in the conservation of Hong Kong's coastal environment. This environment is under serious threat as a result of pollution of marine waters and habitat loss associated with urbanisation, large‐scale reclamation projects, and inadequate treatment and disposal of sewage and industrial effluents. The paper discusses whether in a highly urbanised and stressed environment like Hong Kong, which currently lacks a conservation strategy and an overall framework for handling sustainability issues, small marine parks and reserves can be effective in helping to conserve local biodiversity. The paper also suggests that Hong Kong should adopt a broader regional perspective on its coastal conservation and management problems, a perspective that recognises the significance for the territory of the rapid urban and industrial development taking place in neighbouring Guangdong Province. This will require more extensive and focused liaison with Chinese agencies.

Marine Reserves: Rates and Patterns of Recovery and Decline of Large Predatory Fish

A major objective of the use of marine reserves in management of coral reef fisheries is protection of a critical spawning stock biomass to ensure recruitment supply to fished areas via larval dispersal. However, very little empirical evidence exists on the rates and patterns of increase of density and biomass of target species following the closure of a coral reef or part of a reef, nor on how quickly any gains potentially useful to fisheries can be lost if reserves are subsequently opened to fishing. This paper presents empirical evidence derived from the visual monitoring of density and biomass of large predatory coral reef fish (Serranidae (Epinephelinae), Lutjanidae, Lethrinidae and Carangidae as a group) in two small marine reserves and at two control sites in the Philippines from 1983 to 1993. At one reserve (Sumilon) a complex history of management allowed seven measurements of density and biomass at durations of reserve protection ranging from ‐2 (i.e., fished for 2 yr) to 9 yr. At the second reserve (Apo), seven measurements were taken at durations of reserve protection ranging from 1 to 11 yr. Density of large predators provided an excellent indicator of the effects of marine reserve protection and fishing. Density decreased significantly twice when the Sumilon reserve was opened to fishing (1985, 1993), and increased significantly three times following durations of marine reserve protection of 5 yr (Sumilon reserve and nonreserve sites, 1987‐1991) and &gt;6 yr (Apo reserve beyond 1988). Density of large predators at the Apo nonreserve site (open to fishing) did not change significantly, remaining low throughout the study. Significant positive linear correlations of mean density of large predators with years of reserve protection were observed at both reserves. The rates of increase were 1.15 and 0.72 fish·1000 m‐2·yr‐1 at Sumilon and Apo reserves, respectively, with mean density ranges of ≈ 4‐17 fish/1000 m2 (‐2 to 9 yr of protection) at Sumilon and 0.5‐9.5 fish/1000 m2 (1‐11 yr of protection) at Apo. The pattern of increase of mean biomass with years of reserve protection was more curvilinear than that of mean density, particularly at Sumilon, where a slow increase was observed in the first 3‐5 yr (reflecting delayed recruitment and a natural delay to the period of maximum individual mass growth), followed by an increasing rate over the next 4 yr. Mean biomass ranges were ≈ 1.5‐18 kg/1000 m2 (‐2 to 9 yr of protection) at Sumilon and 1‐10.5 kg/1000 m2 (1‐11 yr of protection) at Apo. At Sumilon reserve, 2 and 1.5 yr of unregulated fishing, respectively, eliminated density and biomass gains accumulated over 5 and 9 yr of marine reserve protection.

Single Large or Several Small Marine Reserves? An Experimental Approach with Seagrass Fauna

One of the most frequently debated theories in conservation biology is whether a Single Large area will preserve more species than Several Small areas of the same total area (the SLOSS debate). We tested this theory in the marine environment by comparing the diversity and abundance of fish and macroinvertebrates associated with small and large seagrass beds. In natural beds, several small beds had significantly more species than a single large bed. This occurred because a large proportion of species were not shared among beds. However, results of experiments using artificial seagrass beds to manipulate size of beds were equivocal. More species and more individuals were found in several small beds on only few occasions in experimental treatments. These results contradicted the patterns found in comparisons among natural beds. Our results stress the need to experimentally validate theories for reserve design and also indicate the danger of directly applying land-based principles to marine communities without critically examining them for each

Patterns of shore utilization in a metropolitan area: The Cape Peninsula, South Africa

A survey of the western shores of False Bay, Cape Peninsula, South Africa (34°5′S, 18°26′W–34°9′S, 18°29′W) was undertaken to determine patterns and intensities of human utilization over a one-year period. This was done as part of a programme to monitor the impact of proclaiming three small marine reserves (created in March 1986) along this intensively utilized stretch of coastline. Only 6% (48 000) of all visitors to the shore were exploiters, i.e. anglers and bait gatherers. The greater proportion of visitors (779 640) engaged in non-exploitative recreational activities, concentrated on sandy beaches. Mean daily shore attendances peaked between 12.00 and 16.00 h. Numbers of visitors during ‘out-of-season’ periods peaked over weekends, with Saturdays being more popular than Sundays. Wednesdays were found to have unexpectedly high attendances. Maximum overall beach attendances occurred during the peak holiday season (the Christmas holidays); but over this period, weekday attendances exceeded those over weekends. Factors influencing the utilization patterns are discussed.