Repeated physical disturbances and the stability of sub‐tropical coral communities in Hong Kong,China

• 1. This paper reports on the dynamics of the coral community structure at A Ma Wan (AMW) and A Ye Wan (AYW) in Tung Ping Chau, Hong Kong, focusing on data collected before and after the summer typhoon seasons in 1997 to 1999. This period (1999) experienced the highest frequency of severe tropical cyclones to hit Hong Kong with one cyclone being the strongest to hit in the last 23 years (1984 to 2006).
• 2. This is part of a long‐term monitoring programme of subtropical coral communities that has been set up in AMW since May 1997 and AYW since May 1998 with nine fixed position 40 m long transects and 0.5 m × 0.5 m permanent quadrats laid at 5 m intervals along each transect. A total of 45 scleractinian coral species from 21 genera (12 families) was recorded, with 40 species in AMW and 32 species in AYW recorded at the beginning of the study.
• 3. Multidimensional scaling ordinations showed distinct spatial variations in the coral communities within and between sites. These variations were probably a result of the differential effects of the repeated cyclone impacts on the communities. Cyphastrea serailia, Goniopora lobata, Montipora peltiformis and Pavona decussata were the dominant species most strongly affected by cyclone impacts at AMW, experiencing a 6.2–16.2% loss of mean area cover during the study period. Some dominant species (e.g. P. decussata) in AYW also experienced a 6.5–14.3% loss of mean area cover within the same period.
• 4. Overall, these coral community structures appeared relatively stable and resistant to repeated physical disturbances. However, they may have low resilience towards more severe disturbances in the future. Preserving the resilience of coral communities/species in Tung Ping Chau should be one of the main goals of coral conservation strategies for the island.

Copyright © 2008 John Wiley & Sons, Ltd.     

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.

     

Prioritizing aquatic conservation areas using spatial patterns and partitioning of fish community diversity in a near‐natural temperate basin

相似文献   

Organic matter derived from kelp supports a large proportion of biomass in temperate rocky reef fish communities: Implications for ecosystem‐based management

1. The relative availability of alternative organic matter sources directly influences trophic interactions within ecological communities. As differences in trophic ecology can alter the productivity of communities, understanding spatial variability in trophic structure, and the drivers of variability, is vital for implementing effective ecosystem‐based management.
2. Bulk stable isotope analysis (δ¹³C and δ¹⁵N) and mass balance calculations were used to examine patterns in the contribution of organic matter derived from macroalgae to food webs supporting temperate reef fish communities in two contrasting coastal waterways on the South Island of New Zealand: Fiordland and the Marlborough Sounds. Ten fish species common to both regions were compared, with up to 40% less organic matter from macroalgae supporting omnivorous species in the Marlborough Sounds. The largest differences in trophic position were found in those species exploited by fisheries.
3. Furthermore, stratified surveys of abundance and species biomass combined with trophic position data were used to calculate regional differences in the contribution of macroalgae to whole fish communities in terms of density of biomass. In Fiordland, over 77% of the biomass of exploited reef fishes was supported by macroalgae, compared with 31% in the Marlborough Sounds.
4. Surveys of macroalgal density and species composition in the two regions indicated that regional differences in trophodynamics may be explained by a lack of macroalgal inputs to the food web in the Marlborough Sounds.
5. The findings demonstrate large regional differences in the incorporation of benthic and pelagic sources of organic matter to food webs supporting reef fish communities, highlighting the need for ecosystem‐based approaches to management to recognize spatial variability in primary production supporting coastal food webs.

     

Scleractinian coral communities of the inner Seychelles 10 years after the 1998 mortality event

相似文献   

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.     

Effects of trap fishing on reef fish communities

• 1. Trap fishing is widespread on coral reefs but the sustainability of this practice is causing concern because it is efficient and unselective. The effects of trap fishing were investigated by comparing fish assemblages among six Caribbean islands subject to different trapping pressures. These ranged from none in Bonaire and Saba increasing through Puerto Rico, St Lucia, Dominica and Jamaica respectively.
• 2. Fish were censused at depths of 5 m and 15 m on fore‐reef slopes by counting the numbers within replicate 10 m diameter areas for 15 min. Between 64 and 1375 counts were made in each country.
• 3. In St Lucia and Jamaica abundance of fish censused on the reef was compared to representation in traps which were visually sampled underwater in the area of fish counts. Twenty‐three traps were sampled in Jamaica and 75 in St Lucia. For some comparisons between these islands, St Lucian sampling effort was reduced to that of Jamaica (23 traps and 112 counts) by randomly sub‐sampling 10 times.
• 4. Traps contained 54 different species in St Lucia and 22 in Jamaica, while there were 90 and 57 respectively in counts. After reducing St Lucian sampling effort to Jamaican levels, an average of 35 species were found in traps and 70 seen in counts. Of these, 76% in St Lucia and 73% in Jamaica were relatively more abundant in traps than they were on the reef.
• 5. Species were considered to be highly susceptible to trapping if the ratio of their abundance in traps compared to that on the reef exceeded 3:1. Trapping pressure was approximately three and a half times greater in Jamaica than St Lucia. After equalizing sampling effort, there was an average of 16 highly trappable species in St Lucia compared to 13 in Jamaica. Species did not always appear highly trappable in both countries. Eleven of St Lucia's highly trappable species were absent from Jamaica (falling to 8.5 on average after equalizing sampling effort), but none vice versa, suggesting that trapping may have contributed to their absence or rarity on Jamaican reefs.
• 6. The Tetraodontiformes, which include many non‐target species, were particularly susceptible to trapping in both countries. Their abundance in the six islands censused was inversely related to trap fishing pressure, as was that of two other non‐target families, butterflyfish (Chaetodontidae) and angelfish (Pomacanthidae).
• 7. To determine whether fish that are common in traps in St Lucia are reaching sexual maturity before capture, size frequency data for 23 species from a sample of trap catches were gathered and examined for their state of maturity. In seven species, more than a third of 705 trapped fish were immature, indicating that trap fishing causes growth over‐fishing (premature removal of fish), and calling into question the sustainability of yields for these species.
• 8. In conclusion, at the intensities seen in this study, trap fisheries cause serious over‐fishing, reduce biodiversity, and alter ecosystem structure. While commonly perceived as low impact, coral reef trap fisheries in the Caribbean and further afield, need tighter regulation and control.

Copyright © 2006 John Wiley & Sons, Ltd.     

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.

     

Preliminary study of community development and scleractinian recruitment on fibreglass artificial reef units in the sedimented waters of Singapore

• 1. Fibreglass was used to make specially designed reef enhancement units (REUs) for three reef sites in Singapore. Units were established in areas measuring approximately 20 × 50 m.
• 2. The units are compact and light enough to be deployed from small boats by scuba divers, and are suitable for shallow reefs with limited visibility.
• 3. The design of the REUs precludes excessive sediment build‐up on the settlement surfaces, while allowing water currents to flow through the system.
• 4. The REUs were monitored monthly over two years to observe community development and scleractinian coral recruitment on the exterior surfaces. Recruitment was compared between REUs and rubble quadrats at one study site.
• 5. The REUs were colonized by turf algae within the first month, followed by crustose coralline algae, macroalgae, ascidians and hydroids. At the end of two years, the percentage cover of crustose coralline algae at all three sites was more than 50%.
• 6. The first incidence of coral recruitment was six months post deployment, and recruitment rates at the end of the monitoring period ranged from 0.10 to 4.75 recruits per square metre for the three sites. Recruits show better survival and growth on REUs compared to rubble areas.
• 7. The most abundant recruit was Pocillopora damicornis, followed by favids, acroporids and poritids.

Copyright © 2006 John Wiley & Sons, Ltd.     

Trouble on the reef: the imperative for managing vulnerable and valuable fisheries

Reef fishes are significant socially, nutritionally and economically, yet biologically they are vulnerable to both over‐exploitation and degradation of their habitat. Their importance in the tropics for living conditions, human health, food security and economic development is enormous, with millions of people and hundreds of thousands of communities directly dependent, and many more indirectly so. Reef fish fisheries are also critical safety valves in times of economic or social hardship or disturbance, and are more efficient, less wasteful and support far more livelihoods per tonne produced than industrial scale fisheries. Yet, relative to other fisheries globally, those associated with coral reefs are under‐managed, under‐funded, under‐monitored, and as a consequence, poorly understood or little regarded by national governments. Even among non‐governmental organizations, which are increasingly active in tropical marine issues, there is typically little focus on reef‐associated resources, the interest being more on biodiversity per se or protection of coral reef habitat. This essay explores the background and history to this situation, examines fishery trends over the last 30 years, and charts a possible way forward given the current realities of funding, capacity, development patterns and scientific understanding of coral reef ecosystems. The luxury live reef food‐fish trade is used throughout as a case study because it exemplifies many of the problems and challenges of attaining sustainable use of coral reef‐associated resources. The thesis developed is that sustaining reef fish fisheries and conserving biodiversity can be complementary, rather than contradictory, in terms of yield from reef systems. I identify changes in perspectives needed to move forward, suggest that we must be cautious of ‘fashionable’ solutions or apparent ‘quick fixes’, and argue that fundamental decisions must be made concerning the short and long‐term values of coral reef‐associated resources, particularly fish, for food and cash and regarding alternative sources of protein. Not to address the problems will inevitably lead to growing poverty, hardship and social unrest in many areas.     

The effects of human activity on the temporal variability of coral reef fish assemblages in the Key Largo National Marine Sanctuary

• 1. A visual assessment method, called Discrete Group Censusing, was used to assess and monitor five coral reef fish assemblages in the Key Largo National Marine Sanctuary, Florida, USA.
• 2. Samples were obtained quarterly from Winter 1988 to Autumn 1990 to investigate a possible relation between the variability of reef fish assemblages and human disturbance.
• 3. Two types of disturbance were studied: a ship grounding that occurred 4 years previous to the study, and intensive, recreational snorkel and SCUBA diving. These disturbances appeared to have no short-term effect on the temporal variability of the reef fish assemblages during the study period.
• 4. Furthermore, the assemblages at all five study sites appeared to be extremely stable over the 2 year period of the study. These results support the theory that coral reef fish assemblages are highly ordered and stable over relatively large spatial scales.
• 5. The Discrete Group Censusing visual assessment method was found to be a valuable and easily applied tool for the nondestructive in situ monitoring of reef fish assemblages on coral reefs.

     

Effectiveness of community and volunteer based coral reef monitoring in Cambodia

1. Globally, coral reef monitoring programmes conducted by volunteer‐based organizations or local communities have the potential to collect large quantities of marine data at low cost. However, many scientists remain sceptical about the ability of these programmes to detect changes in marine systems when compared with professional techniques.
2. A limited number of studies have assessed the efficacy and validity of volunteer‐based monitoring, and even fewer have assessed community‐based methods.
3. This study in Cambodia investigated the ability of surveyors of different levels of experience to conduct underwater surveys using a simple coral reef methodology. Surveyors were assigned to four experience categories and conducted a series of six 20 × 5 m belt transects using five benthic indicator species.
4. Results show decreased variation in marine community assessments with increasing experience, indicating that experience, rather than cultural background, influences survey ability. This suggests that locally based programmes can fill gaps in knowledge with suitable ongoing training and assessment.

Copyright © 2016 John Wiley & Sons, Ltd.     

Evaluating the efficacy of small‐scale marine protected areas for preserving reef health: A case study applying emerging monitoring technology

1. Marine protected areas (MPAs) are widely used as management tools to conserve species and ecosystems at risk from human impact. Coastal managers often focus MPA designation on biogenic reef environments due to their value and sensitivity to damage. However, difficulties in enforcement and a lack of capacity to adequately monitor MPAs often make it hard for managers to assess the effectiveness of MPAs, particularly in under‐resourced, low‐income coastal countries.
2. Reef community data were collected at three long‐term managed reserves within the Western Visayas region of the central Philippines in order to assess the state of reef community structure inside and outside of these small‐scale locally managed MPAs. In addition, 3D structural data were captured using recently developed 'Structure from Motion' photogrammetry techniques, demonstrating how multiple quantitative metrics of physical structural complexity and health can be recorded in such analyses.
3. These community‐run MPAs were shown to be effective even when small (10–20 ha). Mean fish biomass density was five times greater within present‐day protected sites, alongside significantly increased levels of fish diversity, richness, and size. No significant structural differences were observed inside and outside of MPAs; however, average reef rugosity, height, and roughness were significantly higher in unfished reefs compared to blast‐fished reefs. Reef substrate complexity, coral composition, and level of management, were also shown to structure fish community assemblages, with the link between reef structure and fish richness/abundance disrupted outside of MPAs.
4. The Structure from Motion technique allows a greater range of quantitative morphometrics to be assessed than traditional methods and at relatively low cost. The technique is rapid, non‐destructive and can be archived, increasing the value of data for managers wishing to quantify reef health and efficiently monitor benthic changes through time. We discuss both the limitations and benefits of this technology's future use.

     

Response of fish communities to the deployment of estuarine artificial reefs for fisheries enhancement

Understanding succession of fish communities associated with artificial structures is required to assess the potential of these initiatives as part of fisheries enhancement strategies and determine possible impacts on the broader ecological community. Artificial reef systems constructed in three south‐eastern Australian estuaries were monitored over a four‐year period. Recruitment of fish to the artificial reefs was rapid, with significantly greater species richness observed on artificial reefs than on natural habitats for the majority of locations and times. The rate of community change varied between estuaries and appeared to be related to the quality and amount of existing habitat and the distance of the artificial reef from sources of recruitment. General patterns were also identified among estuaries driven by strong recruitment, followed by a rapid reduction in several mobile schooling species. By contrast, there was early and sustained recruitment of a variety of sparid species, which are of importance to recreational and commercial fisheries.     

Response of the riverine fish community to the construction and operation of a diversion hydropower plant in central Chile

• 1. Chilean rivers have a large potential for hydropower development, and they also contain a unique native fish fauna with a high level of endemism. Several diversion hydropower plants have recently been constructed in Chile; however, the response of fish communities to these new hydropower plant designs is not well known.
• 2. Responses of native and non‐native fish to the construction and operation of a new hydropower plant that diverts water from two rivers were quantified. The Laja River is highly regulated and manipulated with three older (40 yr) dam‐based hydropower plants and irrigation diversions located upstream from the new facility. In contrast, the Rucúe River has no other hydropower facilities and is comparatively undisturbed.
• 3. Prior to construction, the Laja River had a fish community with lower species richness compared with the Rucúe River. The fish community structure in the Laja River was dramatically altered after the new hydropower facility began operation. On the other hand, in the Rucúe River, even though abundance of fish declined, there was less of a change in the total fish community structure. The fish community in the Rucúe River exhibited greater resistance to change compared with the Laja River.
• 4. The species most affected were the introduced salmonids and an endangered native species Percilia irwini.
• 5. Although diversion hydropower designs may have less impact than traditional dam‐based hydropower facilities, results of this study indicate that diversion hydropower structures can cause large changes in the fish community.

Copyright © 2006 John Wiley & Sons, Ltd.     

Dynamics of fish assemblages on coral reefs subjected to different management regimes in the Abrolhos Bank,eastern Brazil

• 1. Marine protected areas (MPAs) range from multiple‐use areas (MUA) to absolute no‐take reserves (NTR). Despite their importance for fisheries management, there are few long‐term studies comparing benefits from different types of MPAs within the same region.
• 2. Fish assemblages were monitored for five years (2001–2005) in the largest coral reefs in the South Atlantic (Abrolhos Bank, Brazil). Monitoring included one community‐based MUA, two NTRs (one established in 1983 and another in 2001), and one unprotected area. Benthic assemblages at these areas, as well as fish assemblages on unprotected deeper reefs (25–35 m), were monitored from 2003 onwards.
• 3. Habitat characteristics strongly influenced fish assemblages' structure. This, together with the lack of data from before establishment of the MPAs, did not allow an unequivocal analysis of the effects of the MPAs.
• 4. Biomass of commercially important fish, particularly small carnivores, was higher in the older NTR. Biomass of black grouper Mycteroperca bonaci increased by 30‐fold inside NTRs during the study period, while remaining consistently low elsewhere.
• 5. A single herbivore species, the parrotfish Scarus trispinosus, dominated fish assemblages (28.3% of total biomass). Biomass of this species increased in 2002 on the younger NTR and on the MUA, soon after establishment of the former and banning of the parrotfish fishery in the latter. This increase was followed by a decline from 2003 onwards, after increased poaching and reopening of the parrotfish fishery.
• 6. Fish biomass increased in 2002 across the entire region. This increase was stronger in sites closer to deeper reefs, where fish biomass was up to 30‐times higher than shallow reefs: movement of fish from deeper to shallower areas may have played a role.
• 7. The effective use of MPAs in the Abrolhos Bank is still dependent on adequate enforcement and the protection of critical habitats such as deep reefs and mangroves.

Copyright © 2008 John Wiley & Sons, Ltd.     

Artificial reefs as a reef restoration strategy in sediment‐affected environments: Insights from long‐term monitoring

1. Artificial reefs provide substrates that facilitate the rapid recruitment of marine biota such as corals and fish, and are commonly employed as coral restoration tools to assist recovery in degraded areas. While this strategy is successful in the immediate years post‐deployment, its contribution to restoration over longer time scales is less well understood.
2. The biological communities on Reef Enhancement Units (REUs), which had been deployed for more than a decade on Singapore's sediment‐affected coral reefs, were surveyed.
3. The diversity of sessile lifeforms on the REUs was significantly higher in 2014 (H′ = 1.03) than 2004 (H′ = 0.60). Hard corals and coralline algae contributed most to the temporal dissimilarity and turf algae remained the dominant lifeform category in both years.
4. In 2014, hard corals and abiotic components contributed most to the spatial dissimilarity among the six REU plots that were surveyed. Shannon diversity values of these plots ranged from 0.74–1.3. Scleractinian cover ranged from 0.4–31.5% and differed significantly among the plots.
5. The REUs also augmented ecosystem functioning at their respective plots. Colonies from 10 of the 30 scleractinian genera recorded were sexually mature, and a total of 119 sessile and mobile reef taxa utilized the REUs for food and habitat.
6. The results demonstrate that artificial reefs can contribute to the development of biological communities and ecosystem functioning in degraded coral habitats over the long run, and underscore the need for long‐term monitoring to validate the effectiveness of reef restoration efforts.

     

Fish assemblages of Red Sea backreef biotopes

• 1. Fish assemblages of shallow‐lagoonal biotopes (seagrass beds, coral patches, reef flat and sand) were examined within the Nabq Managed Resource Protected Area (MRPA), South Sinai, Egypt. This protected area supports a small‐scale artisanal Bedouin fishery, managed by gear restrictions and a network of no‐take zones (NTZs).
• 2. Coral patches showed highest species richness and diversity of fish, followed in order by the reef flat, shallow seagrass beds and sandy bottoms.
• 3. There were clear differences in fish assemblages between the biotopes surveyed, little differences between sampling areas and no significant differences in fish assemblages between no‐take and take zones, suggesting species characteristic of these shallow‐water biotopes are dispersed along the coast irrespective of fishing pressure.
• 4. Nine species (Acanthurus nigrofuscus, Asterropteryx semipunctatus, Cryptocentrus caeruleopunctatus, Cheilio inermis, Thalassoma rueppellii, Lethrinus mahsena, Lethrinus nebulosus, Parupeneus forsskali and Pomacentrus trilineatus) had a 95% correlation to the pattern of assemblage distribution, indicating these species are the most important determinants of the fish community.
• 5. Approximately one‐third of fishes recorded appeared to be juveniles, with seagrass beds having a particularly high proportion of juvenile fish, including several commercial species.
• 6. The structure of the fish assemblage and fish size suggests that shallow‐water biotopes in Nabq MRPA may be acting as nursery areas of commercial fish for the Bedouin fishery.

Copyright © 2006 John Wiley & Sons, Ltd.     

Fish fauna in Iberian Mediterranean river basins: biodiversity,introduced species and damming impacts

• 1. A basin approximation was used to analyse distribution patterns of different components of biodiversity (taxonomic richness, endemicity, taxonomic singularity, rarity) and conservation status of freshwater fish fauna in 27 Mediterranean Iberian rivers.
• 2. Basin area alone explained more than 80% of variation in native species richness. Larger basins featured not only a higher number of native species, but also more endemic and rare species and fewer diversified genera than smaller basins.
• 3. In contrast, smaller basins scored higher community conservation values, owing to their lower degree of invasion by introduced species.
• 4. The presence of dams was the most important factor determining the conservation status of fish communities, and it was also positively associated with the number of introduced species.
• 5. While the most important components of Iberian freshwater fish biodiversity are located in large basins, small unregulated basins feature better conserved fish communities.

Copyright © 2004 John Wiley & Sons, Ltd.     

朱家尖人工鱼礁区鱼类和大型无脊椎动物群落结构变动初探

基于2002年朱家尖建礁水域的本底调查和2005～2006年4个航次跟踪调查数据,初步探讨了朱家尖人工鱼礁海域投礁前后鱼类和大型无脊椎动物的组成、优势种和群落结构变化。结果表明,投礁后出现的种类数为投礁前的2.8倍,鱼礁海域采集到鱼类和大型无脊椎动物53种,由鱼类、甲壳类和软体类3大类组成,鱼类和甲壳类分别占调查种类的49%和45%;投礁前后,甲壳类优势种发生了很大变化,从低值虾类转变成以日本（Charybdis japonica）和日本鼓虾（Alpheus japonicus）等经济虾、蟹类为主;甲壳类为拖网渔获的主要构成部分;投礁前后鱼类和大型无脊椎动物种类组成具有相近的群落多样性测度值,但皆未达到中等相似水平,优势种在不同月份差异大。人工鱼礁的建设使石首鱼科种类和岩礁性鱼类增加明显,鱼礁生境既具有维持固有种类的优势,还可为更多生物提供栖息地。