Hermatypic Coral Species Research Articles

Simulating cyanide fishing: photosynthetic effects of short-term cyanide exposure in three different hermatypic coral species

ABSTRACT Since the 1960s the demand for ornamental aquarium fish has grown steadily and consequently cyanide fishing is still a popular fishing method despite its prohibition. This poses a severe threat to coral reefs in Southeast Asia. This study aimed to investigate the short-term stress reaction on photosynthetic yield in the tissues of three different hard coral colonies (branching growth forms Pocillopora damicornis and Seriatopora hystrix, and massive Porites lobata) to initially high and then decreasing cyanide exposure, mimicking cyanide fishing by fishermen. Experiments were performed both in situ in the coral reefs of the Marine Protected Area Pulau Pieh, West Sumatra, Indonesia, and in the aquaria facilities of ZMT in Germany. A Diving-PAM fluorometer was used for in vivo stress assessment of the holobiont. While in all species the photosynthetic efficiency was significantly reduced right after cyanide application, the massive species displayed much lower ΔF/Fm’ values. After three days in cyanide-free water all three coral species recovered to initial values of Fv/Fm, except for P. lobata. No bleaching or discolouration was detected by the conclusion of the experiment after 38 days. Especially Indonesian reefs with massive corals may be therefore more severely impacted by cyanide fishing since the retention time of the water in these reefs is longer than in reefs that consist primarily of branching corals. This might have implications for the management of different reef parts of the MPA.

Characterization of anthropogenic marine macro-debris affecting coral habitat in the highly urbanized seascape of Mumbai megacity

Marine debris has become a major form of pollution and a serious ecosystem health concern. The present study evaluates the accumulation, origin, and fate of debris in intertidal coral habitats of Mumbai-one of the world's highly populated coastal cities on the west coast of India. Predominantly, seven hermatypic coral species belonging to seven genera and five families were identified and mainly represented by Pseudosidastrea, Porites, and Bernardpora. In terms of number, the mean density of marine debris was 1.60 ± 0.13 SE items/m2, which is higher than the global average. The mean density of plastic debris was 1.46 ± 0.14 SE items/m2. Approximately 9% of total coral colonies were in physical contact with debris, and 22% of these colonies showed visible signs of partial bleaching. Single use plastic bags and wrappers were dominant plastic debris. The study area was characterized as ‘very poor cleanliness’ according to the Beach Quality Indexes, which include the Clean Coast Index, General Index, and Hazardous Items Index. The numerical model indicates the influence of river discharge and probable areas of plastic accumulation with high tidal currents in this region, maneuvering the spatial advection of litter in the nearshore areas. Combined analysis of ground-truthing and model simulation implies that the possible contributing sources of litter were representatives of land-based and sea-originated. The overall results point to increasing anthropogenic stressors threatening coastal coral communities, including marine debris pollution. It is advocated to adopt an integrated coastal zone management approach supported by coordinated policy frameworks could guide the mitigation of the debris footprint in coastal environments.

Genetic Structure of the Goniopora lobata and G. djiboutiensis Species Complex Is Better Explained by Oceanography Than by Morphological Characteristics

Species delimitation of closely related corals is often challenging due to high intraspecies morphological variation and phenotypic plasticity with a lack of characteristic features and scarcity of relevant molecular markers. Goniopora spp. are one such coralline group, and the species status of Goniopora lobata and Goniopora djiboutiensis, an Indian and Pacific Ocean hermatypic coral species complex, has been questioned on the basis of previous molecular and morphological analyses. To further examine the species boundaries between G. lobata and G. djiboutiensis in Japan, specimens collected from areas spanning from Ryukyu Island to temperate Japanese regions were morphologically identified based on traditional morphological descriptions. Then, the genetic structure of the G. lobata and G. djiboutiensis species complex was examined using six newly developed microsatellite markers. The majority of the collected specimens had intermediate morphologies, and a STRUCTURE analysis using the LOCPRIOR model based on typical G. lobata and G. djiboutiensis morphology indicated that there were no genetic differences between these morphologies. On the other hand, STRUCTURE analysis based on oceanographic regions revealed that there was a genetic break between the temperate and subtropical regions. This weak genetic break corresponded with the Kuroshio-associated barrier, which prevents larval transport between subtropical and temperate regions. This study confirms that the current morphological identification criteria for G. lobata and G. djiboutiensis do not match the existing genetic boundaries and thus the two should be regarded as a species complex. This study also highlighted the robustness of using a multi-locus population genetic approach, including a geographic context, to confirm the species boundaries of closely related species.

Increasing coral calcification in Orbicella faveolata and Pseudodiploria strigosa at Flower Garden Banks, Gulf of Mexico

Coral reefs are globally in decline and western Atlantic reefs have experienced the greatest losses in live coral cover of any region. The Flower Garden Banks (FGB) in the Gulf of Mexico are high-latitude, remote reefs that are an outlier to this trend, as they have maintained coral cover ≥ 50% since at least 1989. Quantifying the long-term trends in coral growth of key reef-building coral species, and the underlying environmental drivers, leads to a better understanding of local sensitivities to past changes that will ultimately allow us to better predict the future of reef growth at FGB. We obtained coral cores and constructed growth records for two of the most abundant hermatypic coral species at FGB, Pseudodiploria strigosa and Orbicella faveolata. Our records cover 57 yrs of growth for P. strigosa (1957–2013) and 45 yrs for O. faveolata (1970–2014). Linear extension and calcification rates of both species have increased significantly, but skeletal density did not change over the respective time periods. Extension and calcification data of both species combined were negatively correlated with the discharge from the Atchafalaya River, but positively correlated with maximum sea surface temperatures (SST). These data provide evidence that runoff from the Atchafalaya River impacts FGB corals and is a major control on coral growth at FGB. The increase in growth at FGB can be attributed to the significant warming trend in maximum monthly SSTs. Given the warming trend and recent increase in severity of bleaching at FGB, the prognosis is that bleaching events will become more deleterious with time, which will lead to a breakdown in the positive relationship between coral growth and maximum SST. This study provides further evidence that some high-latitude, cooler reef sites have experienced a stimulation in coral growth with ocean warming.

Rapid relative increase of crustose coralline algae following herbivore exclusion in a reef of El Salvador.

The Eastern Tropical Pacific (ETP) is one of the most isolated and least studied regions in the world. This particularly applies to the coast of El Salvador, where the only reef between Guatemala and Nicaragua, called Los Cóbanos reef, is located. There is very little published information about the reef’s biodiversity, and to our knowledge, no research on its ecology and responses to anthropogenic impacts, such as overfishing, has been conducted. The present study, therefore, described the benthic community of Los Cóbanos reef, El Salvador, using the Line-Point-Intercept-Transect method and investigated changes in the benthic community following the exclusion of piscine macroherbivores over a period of seven weeks. Results showed high benthic algae cover (up to 98%), dominated by turf and green algae, and low coral cover (0–4%). Porites lobata was the only hermatypic coral species found during the surveys. Surprisingly, crustose coralline algae (CCA) showed a remarkable total cover increase by 58%, while turf algae cover decreased by 82%, in experimental plots after seven weeks of piscine macroherbivore exclusion. These findings apparently contradict the results of most previous similar studies. While it was not possible to ascertain the exact mechanisms leading to these drastic community changes, the most likely explanation is grazing on turf by small grazing macroherbivores that had access to the cages during the experiment and clearing of CCA initially covered by epiphytes and sediments. A higher CCA cover would promote the succesful settlement by corals and prevent further erosion of the reef framework. Therefore it is crucial to better understand algal dynamics, herbivory, and implications of overfishing at Los Cóbanos to avoid further reef deterioration. This could be achieved through video surveys of the fish community, night-time observations of the macroinvertebrate community, exclusion experiments that also keep out herbivorous macroinvertebrates, and/or experimental assessments of turf algae/CCA interactions.

Thermal tolerance of the hermatypic coral Acropora tenuis elucidated by RGB analysis and expression of heat shock proteins in coral and symbiotic dinoflagellates

Increased seawater temperature has resulted in mass coral bleaching events globally. Acropora tenuis, the dominant hermatypic coral species in southern Japan, was exposed to four temperature treatments [28 °C, 30 °C, 32 °C, and >32 (=33.3 °C)] for 7 d. The coral colour was converted to R (red), G (green), and B (blue) values, each ranging from 0 (darkest) to 255 (brightest). RGB values exposed to 28 °C and 30 °C decreased slightly, whereas those exposed to 32 °C increased significantly after day 3–6, and those exposed to 33.3 °C changed to white within 2 d. Quantitative RT-PCR analysis revealed no significant changes in heat shock proteins in Acropora and symbiotic dinoflagellates at 28 °C and 30 °C after a 7 d exposure. Our findings revealed that 30 °C, higher than the mean temperature of the warmest month in southern Japan, was an inhabitable temperature for A. tenuis.

Early life history of the Caribbean coral Orbicella faveolata (Scleractinia: Merulinidae)

Abstract. Introduction: Rehabilitation of hermatypic coral species that have declined in the Caribbean in recent decades is a priority. Production of sexual recruits is considered the best restoration method to aid affected populations. Objective: To gain knowledge of early life stages of Orbicella faveolata and to enhance production of new sexual recruits. Methods: Gamete bundles from the coral species O. faveolata were collected over three years (2016, 2018, and 2019) from Los Corales del Rosario y de San Bernardo Natural National Park, Cartagena, Colombia. Assisted fertilization, larval rearing, settlement (onto crustose coralline algae, CCA) and post settlement survival in laboratory conditions were monitored. Results: Embryonic and larval development were documented over 55 hours after the first cleavage, when larvae were fully developed and started pre-settlement behavior. Settlement began 7 days after first cleavage and after 37 days polyps had acquired zooxanthellae. Larval settlement was higher on Lythophyllum congestum and Titanoderma prototypum than in response to Porolithon pachydermum, Neogoniolithon sp., Hydrolithon sp., and Lythophyllum sp. Larvae did not settle on dead coral or on the negative control (sterilized seawater). After the first week post settlement survival was 59 % amongst O. faveolata recruits. During the second week, survival dropped to 42 %, and was further reduced to 0 % at the end of the third week. Conclusions: O. faveolata larvae require cues from certain CCA species to settle, they do not settle in absence of CCA. Increased larvae availability is possible through assisted fertilization in the laboratory, however, due to the high mortality in early post-settlement phases, additional research needs to be conducted in order to scale up larvae production and improve understanding of the cues that enhance settlement and the factors which cause post-settlement mortality.

Electrophysiological evidence for light-activated cation transport in calcifying corals.

Light has been demonstrated to enhance calcification rates in hermatypic coral species. To date, it remains unresolved whether calcifying epithelia change their ion transport activity during illumination, and whether such a process is mediated by the endosymbiotic algae or can be controlled by the coral host itself. Using a modified Ussing chamber in combination with H+ sensitive microelectrode measurements, the present work demonstrates that light triggers the generation of a skeleton positive potential of up to 0.9 mV in the hermatypic coral Stylophora pistillata. This potential is generated by a net flux of cations towards the skeleton and reaches its maximum at blue (450 nm) light. The effects of pharmacological inhibitors targeting photosynthesis 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and anion transport 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) were investigated by pH microelectrode measurements in coral tissues demonstrating a rapid decrease in tissue pH under illumination. However, these inhibitors showed no effect on the electrophysiological light response of the coral host. By contrast, metabolic inhibition by cyanide and deoxyglucose reversibly inhibited the light-induced cation flux towards the skeleton. These results suggest that ion transport across coral epithelia is directly triggered by blue light, independent of photosynthetic activity of algal endosymbionts. Measurements of this very specific and quantifiable physiological response can provide parameters to identify photoreception mechanisms and will help to broaden our understanding of the mechanistic link between light stimulation and epithelial ion transport, potentially relevant for calcification in hermatypic corals.

Assessing coral stress responses using microarray

Storms inflict damage to corals resulting in fragments that have the potential to regenerate thus contributing to the asexual reproduction of the parental colony. Extreme climatic events like these are predicted to increase in the future due to ocean warming, which is also the primary cause of coral reef bleaching and consequent coral mortality in the tropical and subtropical seas. This way it is urgent to investigate the differential effect of warming over post-fragmentation and regeneration processes among the scleractinian hermatypic coral species. This study investigated the mortality, growth and regeneration capacity of nine reef-forming coral species of the Indo-Pacific. Fragments were exposed to 26 °C, 30 °C, and 32 °C for 60 days. Half of these fragments was inflicted with one injury and the other half was used as control. Mortality, partial mortality, bleaching level, growth and regeneration of artificial injuries were assessed. Mortality increased with temperature, reaching 100% for most species after 60 days, at 32 °C, but Psammocora contigua which showed remarkably lower mortality (40%) and all coral fragments of Turbinaria reniformis and Galaxea fascicularis survived the experiment. Partial mortality was lowest for P. contigua, T. reniformis, and G. fascicularis even at 32 °C. These three coral species were also the most resistant to bleaching. Growth rates decreased with temperature, with the exception of G. fascicularis that maintained similar growth rates at 26 °C and 30 °C. Regeneration rates generally increased with temperature. It was concluded that P. contigua, T. reniformis, and G. fascicularis fragments show higher capacity to withstand higher temperatures.

Mortality, growth and regeneration following fragmentation of reef-forming corals under thermal stress

Storms inflict damage to corals resulting in fragments that have the potential to regenerate thus contributing to the asexual reproduction of the parental colony. Extreme climatic events like these are predicted to increase in the future due to ocean warming, which is also the primary cause of coral reef bleaching and consequent coral mortality in the tropical and subtropical seas. This way it is urgent to investigate the differential effect of warming over post-fragmentation and regeneration processes among the scleractinian hermatypic coral species. This study investigated the mortality, growth and regeneration capacity of nine reef-forming coral species of the Indo-Pacific. Fragments were exposed to 26 °C, 30 °C, and 32 °C for 60 days. Half of these fragments was inflicted with one injury and the other half was used as control. Mortality, partial mortality, bleaching level, growth and regeneration of artificial injuries were assessed. Mortality increased with temperature, reaching 100% for most species after 60 days, at 32 °C, but Psammocora contigua which showed remarkably lower mortality (40%) and all coral fragments of Turbinaria reniformis and Galaxea fascicularis survived the experiment. Partial mortality was lowest for P. contigua, T. reniformis, and G. fascicularis even at 32 °C. These three coral species were also the most resistant to bleaching. Growth rates decreased with temperature, with the exception of G. fascicularis that maintained similar growth rates at 26 °C and 30 °C. Regeneration rates generally increased with temperature. It was concluded that P. contigua, T. reniformis, and G. fascicularis fragments show higher capacity to withstand higher temperatures.

Calcification of the main reef-building coral species on the Pacific coast of southern Mexico

Global warming and ocean acidification affect coral calcification. Nevertheless, there is not enough information regarding the growth parameters of the main reef-building coral species in marginal growth areas such as the Pacific coast of southern Mexico. In order to fill this gap, coral growth parameters of 8 hermatypic coral species (massive species: Porites panamensis, Porites lobata, Pavona gigantea, and Pavona varians; branching species: Pocillopora meandrina, Pocillopora damicornis, Pocillopora verrucosa, and Pocillopora capitata) were estimated in 2 areas of the southern Mexican Pacific. Branching coral species had a higher calcification rate (2.99–5.23 g CaCO3 cm–2 yr–1) than massive species (0.34–1.13 g CaCO3 cm–2 yr–1). A significant relation between sea surface temperature (SST) and skeletal density was observed in all massive coral species. Also, 2 massive species (P. gigantea and P. varians) showed a significant relation between SST and calcification rate. Upwelling in the Gulf of Tehuantepec transports deep water with low pH and low aragonite saturation, and may be affecting the calcification rate of stony corals in the studied area.

Seasonal mesophotic coral bleaching of Stylophora pistillata in the Northern Red Sea.

Coral bleaching occurs when environmental stress induces breakdown of the coral-algae symbiosis and the host initiates algae expulsion. Two types of coral bleaching had been thoroughly discussed in the scientific literature; the first is primarily associated with mass coral bleaching events; the second is a seasonal loss of algae and/or pigments. Here, we describe a phenomenon that has been witnessed for repeated summers in the mesophotic zone (40–63 m) in the northern Red Sea: seasonal bleaching and recovery of several hermatypic coral species. In this study, we followed the recurring bleaching process of the common coral Stylophora pistillata. Bleaching occurred from April to September with a 66% decline in chlorophyll a concentration, while recovery began in October. Using aquarium and transplantation experiments, we explored environmental factors such as temperature, photon flux density and heterotrophic food availability. Our experiments and observations did not yield one single factor, alone, responsible for the seasonal bleaching. The dinoflagellate symbionts (of the genus Symbiodinium) in shallow (5 m) Stylophora pistillata were found to have a net photosynthetic rate of 56.98–92.19 µmol O2 cm−2 day−1. However, those from mesophotic depth (60 m) during months when they are not bleached are net consumers of oxygen having a net photosynthetic rate between −12.86 - (−10.24) µmol O2 cm−2 day−1. But during months when these mesophotic corals are partially-bleached, they yielded higher net production, between −2.83–0.76 µmol O2 cm−2 day−1. This study opens research questions as to why mesophotic zooxanthellae are more successfully meeting the corals metabolic requirements when Chl a concentration decreases by over 60% during summer and early fall.

Artificial Cultivation of Hermatypic Corals on Experimental Frame on the Reefs of Vietnam

In 2003-2005 and 2010-2011, experimental commercial cultivation of 14 species of hermatypic corals was carried out using the method of donor colony fragmentation. The transplants successfully survived on experimental frame installations. The coral colonies that were recovered from the fragments became attached to the frame installations in a similar way to their attachment on natural substrata. The research has established species-specific factors and others affecting regeneration of fragments and growth of new colonies in these coral species. The accretion of donor fragments and new branches averaged from 40 to 160 mm per year, depending on the coral species, colony size, and season of transplantation. An average monthly accretion of medium and larger transplants and growth of new branches were 1.2-1.3 times higher at spring cultivation than at autumn transplanting. When transplanted, coral fragments of medium and larger sizes survived well and showed higher growth rates in all species studied. After 1-1.5 year, the size of the transplants was found to have increased by 220-275%. The newly formed artificial coral community was colonized by the damselfish Dascyllus reticulates (Pomacentridae).

Bleaching: The Driving Force of Scleractinian New Recruitment at Little Andaman Island, Andaman and Nicobar Islands

Peak bleaching of corals was seen in 2010 in the Andaman and Nicobar Islands. The results were observed as adverse impacts on the reef environment. Little Andaman Island is the southern-most part of Andaman group of Islands. The continental shelf of this island showed a limited number of scleractinian corals as new recruitment at the destroyed reef areas after the 2004 tsunami. Only 34 species of hermatypic corals were reported in 2009. Consecutive underwater survey and experimental outcome reveals that 124 species of scleractinian corals were identified from the same areas after the mass bleaching effect. The presence of species composition of the study area is near about 4 times higher than the study which was made on newly recruited corals after tsunami. Bleaching was the only giant event which occurred in between 2009 and 2012, considered as the prime regulator for the new recruitment of scleractinians. The Shannon–Weaver’s species diversity index of the study area ranges from 5.09 to 6.00, Simpson’s species density index varies from 0.94 to 0.97 whereas the Pielou’s evenness index shows the results in between 0.93 and 0.98. The present paper depicts the species composition, diversity, density and evenness at post bleaching state to signify the constructive role of bleaching towards the settlement of new scleractinian coral life on the preceding places.

Experimental artificial cultivation of corals from colony fragments

In 2010–2011, experimental commercial cultivation of 14 species of hermatypic corals was carried out using the method of donor colony fragmentation. The transplants successfully survived on experimental frame installations. The coral colonies that were recovered from the fragments became attached to the frame installations in a similar way to their attachment on natural substrata. After 1 year, the size of the trans-plants was found to have increased by 275%. The newly formed artificial coral community was colonized by the damselfish Dascyllus reticulates (Pomacentridae); the species is a common coral fish species that lives on natural reefs.

Spatial differentiation of coral species related to wave energy along the Changqi coast, Hainan island, southern China

The regularities of the composition and the spatial distribution of hermatypic coral community is an essential aspect of coral reef ecosystem studies. The relationship between the structure and spatial distribution of hermatypic coral communities and hydrodynamics and wave energy, along the Changqi coast, are investigated. Differences in abundance of hermatypic coral species, at different depths, were found; these were related mainly to the varying influence of waves. Under average weather conditions, the wave energy was dissipated regularly at a depth of 2m. Here, the coral cover was the lowest of all of the depths. However, corals growing in that area is adapted to the conditions; therefore, wave damage was low. The areas at 5–6m water depth were influenced by waves primarily during episodes of extreme weather, with high wave energy resulting in severe damage of the corals. The coral cover in this depth was the highest observed, but the corals were generally smaller and had a short growth period. These findings indicate that the strong waves damaged particularly the weak corals, such as Acropora sp. and Montipora sp., during these short term events. Nevertheless, upon the return of normal conditions, coral communities can grow back and reproduce asexually in the damaged areas. As a result of this regrowth, Acropora sp. and Montipora sp. were highly abundant in areas at a depth of 5m. It appears that knowledge on the physical setting, i.e. the relationship between wave properties and the spatial distribution patterns of corals, is essential for understanding coral reef succession rules; likewise, protection and recovery mechanisms of the coral reef ecosystem.

Analysis on variation trend of coral reef in Xisha

Xisha Islands, located in the northern part of South China Sea, consist of more than 20 islands and atolls. The coral reef of Xisha Islands belongs to the typical ocean distribution of world’s coral reefs, its ecosystem is the most typical in our country and hermatypic coral species are about three-quarters of the total coral species in China. It is addressed with the oldest coral reef community which of the most original and valuable in China. The previous research shows that the islands studded in South China Sea such as Xisha Islands have important influence on the formation of coral reefs along the mainland coast by multiplying and migrating from south to the north. It is supplementary sources of coastal coral larvae in Hainan and Guangdong. Therefore, carrying out the monitoring of coral reef community ecosystem is of great significance to the ecological protection. By the Manta tow and the Line Intercept Transect method, five stations (Xisha Yong xing dao, Shi dao, Xisha zhou, Zhao Shu dao and Bei dao) on Xisha ecological monitoring area were monitored continually from 2005 to 2009. We compared the index changes of Hermatypic coral’s species, coverage and recruitment, and combining with Condition Index, Succession Index, and the variation trend of hard coral in Xisha were analyzed. The results show that, from 2005 to 2009, the coverage of living hermatypic corals in ecological monitoring area is sharply reduced from 68.19% to 7.93%, while the dead coral coverage is sharply increased from 4.70% to 72.90%. Coral recruitment is reduced from 1.18 ind/100 m 2 to 0.07 ind/100 m 2, hermatypic coral species decreased from 87 to 35. In 2005, the health of coral reefs was very good, and the Condition Index was 1.097. However, the Condition Index cut down to a very low degree in 2009. It was only −0.880. The Succession Index belonged to “very low degree” from 2005 to 2009, and the numerical value was gradually reduce from −0.984 to −1.876. As a whole, hermatypic corals are serious degrade regionally and caused great change to the coral structure and biodiversity, this will lead to a continuous degradation of coral reefs.

First observed severe mass bleaching in Malaysia, Greater Coral Triangle

[Extract] Malaysia contains approximately 4,000 km2 of reef (Wilkinson 2008) and an estimated 500 hermatypic coral species, which constitutes more than 60% of the worlds described hermatypic coral species (Veron et al. 2009). However, these reefs are exposed to numerous anthropogenic pressures and more than 40% are classified as having a high or very high Integrated Threat Index (Burke et al. 2002). Prior to 2010, severe and widespread coral bleaching had not been observed on Malaysian reefs, including during the 1997/98 global event when bleaching of Malaysian reefs was mild and occurred only in localized patches (Wilkinson 1998; Kushairi 1999).

Nearshore corals of the Coffs Harbour region, mid north coast, New South Wales.

The occurance and distribution of hermatypic coral species in both the littoral and sublittoral areas at nearshore locations in the Coffs Harbour region were recorded and evaluated. Total species count for the area was 16 with the greatest abundance occurring on the sheltered, northern sides of headlands. Colonies displayed evidence of damage from interactions with macrophytes and from sand deposition.

Ecological environment changes in Daya Bay, China, from 1982 to 2004

Data collected from 12 marine monitoring stations in Daya Bay from 1982 to 2004 reveal a substantial change in the ecological environment of this region. The average N/P ratio increased from 1.377 in 1985 to 49.09 in 2004. Algal species changed from 159 species of 46 genera in 1982 to 126 species of 44 genera in 2004. Major zooplankton species went from 46 species in 1983 to 36 species in 2004. The annual mean biomass of benthic animals was recorded at 123.10 g m −2 in 1982 and 126.68 g m −2 in 2004. Mean biomass and species of benthic animals near nuclear power plants ranged from 317.9 g m −2 in 1991 to 45.24 g m −2 in 2004 and from 250 species in 1991 to 177 species in 2004. A total of 12–19 species of hermatypic corals and 13 species of mangrove plants were observed in Daya Bay from 1984 to 2002.