Herbivorous fishes and the potential of Caribbean marine reserves to preserve coral reef ecosystems

• 1. The development of macroalgae to the detriment of corals is now one of the major threats to coral reefs. Herbivorous fishes are partly responsible for algal regulation on coral reefs and their overexploitation favours the shift from scleractinian coral‐dominated systems towards macroalgae‐dominated systems.
• 2. Marine protected areas (MPAs) that have been established worldwide may benefit coral reefs through the maintenance of high densities of herbivorous fishes which regulate algal growth.
• 3. The paper assesses whether small MPAs in the Caribbean are able to enhance herbivorous fish stock and by controlling macroalgae help to maintain reef ecosystems. A visual census using band‐transects was undertaken around Guadeloupe island where marine reserves have been in place since 1979. The effects of MPAs on both benthic communities and herbivorous fishes are examined.
• 4. Inside MPAs, herbivorous fish biomass was almost twice as high as outside MPAs and macroalgal cover was significantly lower. Fish size class distributions revealed that large individuals occurred mainly inside MPAs and that few male individuals were found outside MPAs. Copyright © 2010 John Wiley & Sons, Ltd.

     

Effects of swim‐with‐dolphin tourism on the behaviour of spinner dolphins,at Samadai Reef in the Egyptian Red Sea

1. Spinner dolphins, Stenella longirostris, are the primary target for marine mammal tourism in Egypt. The present study investigated the short‐term effects of tourist presence on the behaviour of spinner dolphins at Sha'ab Samadai (Samadai Reef), in the southern Egyptian Red Sea.
2. The reef has a large central lagoon where a population of spinner dolphin regularly rest from mid‐morning to mid‐afternoon; visitors are permitted to snorkel in the southern part of the lagoon, but not in the northern closed zone that the dolphins mainly use.
3. Dolphin behaviour was monitored both on days when tourist boats were present and on days when they were absent. In the presence of tourists the proportion of time that the dolphins spent resting was reduced by two‐thirds, whereas the times spent milling, travelling, and showing avoidance behaviour all increased.
4. Furthermore, upon using Markov chain modelling to investigate the effect of tourist presence on the transition probabilities between dolphin activity states, significant changes were found in 10 of the 25 possible behavioural transitions, including increased probabilities of transitioning from resting to milling or travelling, from milling to travelling or avoiding, and from travelling to avoiding.
5. These findings raise concerns that despite the management measures in place, tourist activities affect the dolphins’ behaviour to a greater extent than was previously apparent, with potential long‐term negative effects on their energy budget. The study led to proposals for amending the zoning of the site and for strengthening the regulations for tourist vessels.

     

Frameworks for marine conservation — non‐hierarchical approaches and distinctive habitats

• 1. Conservation efforts have traditionally been directed to ‘flagship’ species (whales, seals, migratory birds, etc.) that capture public attention. Often these flagship species occupy distinctive habitats. Distinctive habitats appear to be distinguished because of anomalous physical structures and unique oceanographic processes occurring within them, whereas representative habitats are not notable in this way. Distinctive habitats are found in areas of various physical anomalies described primarily by temperature, chlorophyll and topography.
• 2. Several different kinds of distinctive habitats can be defined by their anomalous physical structures and oceanographic and biological processes. Species diversity may be either higher or lower in distinctive than in representative habitats. Distinctive habitats predominantly belong to a class of environments called ‘ergoclines’, and are typically associated with elevated resources at some ‘trophic level’.
• 3. These elevated resources may be either the product of true production (i.e. they are generated (in situ), or they are the product of physical accumulation due to circulation mechanisms. These processes lie at the heart of the ecology of distinctive habitats, and are fundamental to maintenance of ecosystem health, ecological integrity, distributions, abundances and recruitment of species, patterns of animal migrations, and potential or actual fisheries yields.
• 4. Conservation strategies need to examine the relationships between distinctive and representative habitats and species diversity. A strategy, leading from studies on flagship or other focal species, could have several advantages. It should rejuvenate the inherent appeal and significance of ‘species’ approaches to marine conservation, provide a rationale for human interest and a new foundation for examination of marine ecological interactions. It would also require a novel synthesis of relationships between ‘species’ and ‘spaces’ approaches to marine conservation by asking how we can take the best advantage of both approaches, rather than seeing them as in conflict.

Copyright © 2002 John Wiley & Sons, Ltd.     

Alien turf: Overfishing,overgrazing and invader domination in south‐eastern Levant reef ecosystems

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Environmental models for predicting habitat of the Indo‐Pacific humpback dolphins in Fujian,China

1. The coast of Fujian Province is a key area for the Indo‐Pacific humpback dolphin (Sousa chinensis), but the characteristics of their preferred habitats are poorly defined.
2. The species distribution model, MaxEnt, was used to predict suitable habitat distributions of humpback dolphins in Fujian, China. The model indicated that the distance to the coastline (63.5% contribution), chlorophyll‐a levels (20.2%) and the bathymetry (15.6%) were important predictors of humpback dolphin habitats.
3. The model predicted 2,043.96 km² of highly suitable habitat that was concentrated in five areas. Four are known to be within the area of the current distribution of humpback dolphins; Putian was identified as a new area with suitable habitat, however, it is unclear if dolphins are present.
4. The predicted locations of suitable humpback dolphin habitats provided in this study should be the focus of future research and nature reserve designs.

     

Knock‐on effects of national risk assessments on the conservation of global biodiversity

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Biogeographical and ecological context for managing threats to coral and rocky reef communities in the Lord Howe Island Marine Park,south‐western Pacific

• 1. Quantitative subtidal surveys of fishes, macro‐invertebrates and sessile organisms at 33 sites within the Lord Howe Island Marine Park revealed a rich fauna and flora, including 164 fishes, 40 mobile invertebrate taxa, 53 coral and other sessile invertebrate taxa, 32 algal taxa, and two seagrasses. The biota in this newly‐zoned marine park was overwhelmingly tropical when species lists were tabulated; however, species with distributions centred on temperate coasts of eastern Australia and New Zealand occurred in disproportionately high densities compared with the tropical species.
• 2. Lord Howe Island reefs were generally in good condition. Virtually no bleached coral was observed (0.2% of the reef surface; 0.8% of total hard coral cover). Living scleractinian coral comprised the predominant group of organisms growing on reef surfaces, with 25.5% cover overall. Other major taxa observed were brown algae (18.8% cover) and red algae (16.9% cover).
• 3. Three distinctive community types were identified within the marine park—coral reefs, macroalgal beds and an offshore/open coast community. The distribution of these community types was strongly related to wave exposure, as indicated by an extremely high correlation with the first principal coordinates axis for biotic data (R²=0.80).
• 4. The close (<3 km) proximity of tropical coral and temperate macroalgal community types off Lord Howe Island is highly unusual, with localized patterns of nutrient enrichment suggested as the primary cause. The macroalgal community type is only known from a small area off the south‐western coast that is not protected from fishing. This community is considered highly susceptible to threats because of potential impacts of global warming and the possibility of expansion of sea urchin barrens. Coral bleaching and ocean acidification associated with global climate change also threaten the coral reef community, which includes relatively high numbers of endemic and near endemic fish species. Copyright © 2009 John Wiley & Sons, Ltd.

     

Food risk trade‐off in the Indo‐Pacific humpback dolphin: An exploratory case study

1. Based on optimal foraging theory, animals are expected to maximize foraging benefits whilst minimizing risks. Despite risking being subjected to anthropogenic impacts such as water contamination, marine traffic, and underwater noise, estuaries have been identified as the preferred habitat of the Indo‐Pacific humpback dolphin (Sousa chinensis, IPHD). However, it remains unclear why this vulnerable species favours such risky habitats.
2. Here, an exploratory case study in Zhanjiang estuary, China, was conducted to test the hypothesis that IPHDs select estuarine habitats as a trade‐off that maximizes foraging opportunities whilst minimizing the risk of mortality.
3. The results showed that IPHDs accept greater mortality risks for higher food rewards but select habitats with lower risks when food rewards are similar between two locations.
4. Although this type of information is important for underpinning models for individual dolphins, its principal role is to show environmental protection agencies why IPHDs favour estuaries despite the increased mortality risks.
5. Habitat conservation plans should carefully consider prey stocks, possibly through the presence of marine protected areas near estuaries, as local overfishing may lead vulnerable cetacean populations to take greater risks.

     

Fishery benefits from behavioural modification of fishes in periodically harvested fisheries closures

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Changes in a coral reef fishery along a gradient of fishing pressure in an Indonesian marine protected area

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The use of volunteers for conducting sponge biodiversity assessments and monitoring using a morphological approach on Indo‐Pacific coral reefs

• 1. Sponges are an important component of coral reef ecosystems, but even though they are widespread with the ability to significantly influence other benthic community members they rarely feature to any great extent in current monitoring or biodiversity assessment programmes conducted by volunteer and professional groups. This exclusion is usually because of the taxonomic problems associated with sponge identification.
• 2. A potential alternative to monitoring temporal or spatial change in sponge assemblages and assessing biodiversity levels is to characterize sponges using morphologies present rather than collecting species data. Quantifying sponge biodiversity (for monitoring and biodiversity assessments) at the morphological level is less time and resource consuming than collecting species data and more suited to groups with little training and experience of sponge taxonomy or in regions where detailed taxonomic information on sponges is sparse.
• 3. This paper considers whether the same differences and similarities in sponge richness and assemblage composition can be identified using species and morphological data in response to environmental gradients at two coral reef ecosystems in south‐east Sulawesi, Indonesia, and whether volunteers can be used to reliably collect morphological information. Sponge morphologies were classified into 14 groups and different morphological assemblages were found by the author at the two sites and between depth intervals. Comparisons of sponge species and morphological composition data showed that common patterns in assemblage structuring and richness could be identified irrespective of whether morphological or species data were used. In addition, a positive linear relationship was found between sponge species and morphological richness.
• 4. The morphological data recorded by volunteer divers (n=10) were compared with that collected by the author. Although volunteers recorded fewer sponges than the author (approximately 15% less), missing mainly small encrusting specimens, similar assemblage structure could be identified from both the volunteers' and the author's data.
• 5. The results showed that the same differences in sponge assemblages between sites and depths could be identified from both species and morphological data. In addition, these morphological data could be reliably collected by volunteer divers.

Copyright © 2006 John Wiley & Sons, Ltd.     

Progress,opportunities and challenges for marine conservation in the Pacific Islands

1. The people of the Pacific have long relied on the ocean for sustenance, commerce and cultural identity, which resulted in a sophisticated understanding of the marine environment and its conservation.
2. The global declines in ocean health require new and innovative approaches to conserving marine ecosystems. Marine Protected Areas (MPAs) have been shown to be a highly effective means of conserving biodiversity and managing fisheries, while also restoring and preserving overall ecosystem function.
3. Traditional ecological knowledge held by many island peoples in the Pacific is critical to the development, design and implementation of contemporary MPAs.
4. Chile's offshore islands are among the few oceanic archipelagos along the west coast of South America. These islands have cultural and ecological connections to the broader insular Pacific, yet our scientific understanding of them is extremely limited.
5. Chile has created several large-scale MPAs around their offshore archipelagos. By protecting these unique ecosystems, Chile has established itself as a global leader in marine conservation.
6. Effective management and a better understanding of social–ecological interactions are currently the biggest challenges facing MPAs in the Pacific Islands.

     

Characterising reef fish populations and habitats within and outside the US Virgin Islands Coral Reef National Monument: a lesson in marine protected area design

Abstract  Marine protected areas are an important tool for management of marine ecosystems. Despite their utility, ecological design criteria are often not considered or feasible to implement when establishing protected areas. In 2001, the Virgin Islands Coral Reef National Monument (VICRNM) in St John, US Virgin Islands was established by Executive Order. The VICRNM prohibits almost all extractive uses. Surveys of habitat and fishes inside and outside of the VICRNM were conducted in 2002–2004. Areas outside the VICRNM had significantly more hard corals, greater habitat complexity, and greater richness, abundance and biomass of reef fishes than areas within the VICRNM. The administrative process used to delineate the boundaries of the VICRNM did not include a robust ecological characterisation of the area. Because of reduced habitat complexity within the VICRNM, the enhancement of the marine ecosystem may not be fully realised or increases in economically important reef fishes may take longer to detect.     

Conservation of threatened species in the Galapagos Marine Reserve through identification and protection of marine key biodiversity areas

• 1. The Galapagos Marine Reserve provides refuge for numerous threatened marine species, including 16 mammals, birds, reptiles and fish currently recognized on the 2006 IUCN Red List of Threatened Species, plus an additional 25 endemic fish, mollusc, crustacean, echinoderm, coral and macroalgal species that comply with threatened species criteria because of declining extent of occurrence or highly‐localized ranges, and hence also qualify for inclusion on the Red List.
• 2. Threatened marine species with restricted ranges are not randomly distributed across the archipelago but tend to co‐occur at a limited number of sites that are predominantly located in the west. Sites at which threatened species are known to persist, particularly those with a large proportion of the global population, are here identified as sites of global conservation significance — key biodiversity areas.
• 3. The majority (27) of the 38 inshore key biodiversity areas identified are currently protected from fishing because they lie within the 17% of coastal waters that is zoned as ‘no‐take’ tourism or conservation zones. All key biodiversity areas should be protected from extractive exploitation if threatened species are to be safeguarded. This can be achieved, at the minimum, through a relatively minor amendment to the existing marine zoning scheme, whereby an additional 2% of the coastline is dedicated to conservation.

Copyright © 2008 John Wiley & Sons, Ltd.     

Cold‐water coral Madrepora oculata in the eastern Ligurian Sea (NW Mediterranean): Historical and recent findings

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Changes in northern Tanzania coral reefs during a period of increased fisheries management and climatic disturbance

• 1. Surveys of coral reefs in northern Tanzania were conducted in 2004/5 with the aim of comparing them over an～8‐year period during a time of increased efforts at fisheries management and the 1998 El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) coral mortality event that caused 45% mortality in northern Tanzania and much of the Indian Ocean.
• 2. Changes associated with both management, its absence, and the ENSO were found but changes were generally small and ecological measures indicated stability or improvements over this period, particularly when compared with reports from much of the northern Indian Ocean.
• 3. Fisheries management in two areas increased the biomass of fish and benthic communities. A small fisheries closure (0.3 km²) displayed little change in the coral community but ecological conditions declined as measured by sea urchins and fish abundances. This change may be associated with its small size because similar changes were not measured in the large closure (28 km²).
• 4. The few sites without any increased management were still degraded and one site had experienced a population explosion of a pest sea urchin, Echinometra mathaei.
• 5. The lack of significant changes across this disturbance indicates that these reefs are moderately resilient to climate change and, therefore, a high priority for future conservation actions.

Copyright © 2009 John Wiley & Sons, Ltd.     

Requirements for marine protected areas to conserve the biodiversity of rocky reef fishes

• 1. This study describes spatial patterns in the biodiversity (species, assemblages) of rocky reef fishes at a spatial scale relevant to management, and compared the outcomes for this biodiversity from alternative procedures for selecting marine protected areas (MPAs) and from the selection of MPAs for fisheries‐related objectives.
• 2. The study area included 104 species in two assemblage types; 36 species and 14 species occurred only in one or two locations respectively.
• 3. MPAs selected by hotspot richness, greedy richness complementarity, and summed irreplaceability included similar percentages of species and significantly more species than randomly selected MPAs. A combined species‐assemblage selection ensured representation of assemblage diversity. Representation of all species and assemblage types required 92% of locations.
• 4. MPAs chosen using density of all fishes or density of exploitable fishes as selection criteria included fewer species (than MPAs selected using species identity) and the percentage of species accumulated did not differ from a random selection.
• 5. Use of an established MPA as the seed for an expanded network was inefficient, leading to additional locations being required and an accumulation of species that did not differ from a random selection.
• 6. The smallest MPA network that fulfilled multiple management objectives (representation of assemblage diversity and majority of species, population viability, support for fisheries, connectivity) required 30% of the surveyed locations.
• 7. This study concluded that: MPAs selected without the benefit of data on intra‐habitat variation in species assemblages will be unrepresentative; the upper range of currently promoted targets for MPA establishment (i.e. 30%) should be regarded as a minimum for biodiversity conservation; MPAs selected for fisheries‐related reasons may not provide expected benefits for the remainder of the fish assemblage.

Copyright © 2006 John Wiley & Sons, Ltd.     

Changes in life history and ecological characteristics of coral reef fish catch composition with increasing fishery management

Abstract Length, life history and ecological characteristics of landed fish communities were studied over a 10‐year period to test theories of fishing disturbance during a time of increased gear and closure management in heavily utilised fisheries. It was predicted that with greater management restrictions: (1) the earliest and fastest responses in the fishery will be seen in those species with faster turnovers, or relatively lower vulnerabilities to fishing; (2) the fishery would transition to a landed catch with higher mean trophic levels, and greater mean body lengths. In addition, the removal of a non‐selective, small‐mesh seine nets should benefit the catch of gears that previously had the greatest species selectivity overlap with the seine net. Many predictions were supported, although maximum lengths and lengths at maturity responded more rapidly than anticipated. The response to eliminating the non‐selective seine net was a more rapid increase in sizes caught by gears with a larger overlap in size (hook and lines) than species selectivity (gill nets). The simultaneous comparison of management systems over time indicates that open‐access fishing grounds can benefit from restrictions imposed in adjacent fishing grounds. The study indicated that multi‐species coral reef fisheries management objectives of maximising yields, as well as maintaining the fish community’s life‐history diversity, require management trade‐offs that balance local socio‐economic and biodiversity needs.     

A spatio‐temporal long‐term assessment on the ecological response of reef communities in a Caribbean marine protected area

1. Coral reef biodiversity is rapidly decreasing as a result of the loss of coral cover, which modifies the structure and functioning of the ecosystem. Understanding how coral reef communities respond in space and over the long term is essential in order to implement management strategies and reduce the effects of biodiversity loss on coral reefs.
2. Fish, coral, and algae communities were used as indicators to evaluate changes in coral reef systems. The variation of these communities was studied in a marine protected area composed of three management zones in Cozumel Coral Reef National Park in Quintana Roo, Mexico, over a period of 11 years (2004–2014). The following parameters were monitored annually: (i) total fish density; (ii) fish trophic group densities; (iii) species richness and three fish diversity indices; (iv) relative scleractinian coral cover; and (v) relative macroalgae cover.
3. In the years in which coastal development, such as the construction of a marina, took place, an increase in the abundance of territorial herbivorous and planktivorous fish was observed. As the coral recovered, macrocarnivores and sessile benthic invertivores were re‐established, whereas scraper herbivores showed no changes in the period of study in any of the three management zones.
4. Coral cover recovery showed rapid phase‐shift reversal (phase‐shift, macroalgae dominance over coral) in the three zones. Even though the fish density and coral cover recovered, the diversity indices of each fish trophic group exhibited a reduction in the three management zones over time.

     

Beyond the reef: The widespread use of non‐reef habitats by coral reef fishes

Marine ecology seeks to understand the factors that shape biological communities. Progress towards this goal has been hampered by habitat‐centric approaches that ignore the influence of the wider seascape. Coral reef fishes may use non‐reef habitats (e.g. mangrove and seagrass) extensively, yet most studies have focused on within‐reef attributes or connectivity between reefs to explain trends in their distribution and abundance. We systematically review the evidence for multihabitat use by coral reef fishes across life stages, feeding guilds and conservation status. At least 670 species of “coral reef fish” have been observed in non‐reef habitats, with almost half (293 species) being recorded in two or more non‐reef habitats. Of the 170 fish species for which both adult and juvenile data were available, almost 76% were recorded in non‐reef habitats in both life stages. Importantly, over half of the coral reef fish species recorded in non‐reef habitats (397 spp.) were potential fisheries targets. The use of non‐reef habitats by “coral reef” fishes appears to be widespread, suggesting in turn that attempts to manage anthropogenic impacts on fisheries and coral reefs may need to consider broader scales and different forms of connectivity than traditional approaches recommend. Faced with the deteriorating condition of many coastal habitats, there is a pressing need to better understand how the wider seascape can influence reef fish populations, community dynamics, food‐webs and other key ecological processes on reefs.