Limpets as prey: Lipophrys pholis choice for size

Patellid limpets are key species on rocky shores, structuring intertidal assemblages through their grazing. Their role as prey for fish is, however, often overlooked in studies of intertidal ecosystem functioning. The shanny Lipophrys pholis is a common predator of limpets on rocky shores in Northern Europe and, in this study, we examined the characteristics of its predation on limpets based on prey size. The limpet size range that adult L. pholis (10–12.5 cm) can eat was examined in the laboratory using Patella depressa in 0.2 cm classes, varying between 0.5 cm and 3.0 cm in maximum shell length. There was a limpet size refuge above 1.8 cm, while all smaller sizes were readily consumed by the shanny. The predator attacking behaviour was also examined and found to vary with prey size. Limpets up to 0.8 cm were crushed by the jaw‐constricting force and eaten whole, whereas larger prey were prised from the substratum and the body subsequently separated from the shell. To examine whether there was a L. pholis preference for P. depressa size, a two‐stage laboratory experiment was done using two size classes defined as small (0.7–0.8 cm maximum shell length) and large (1.5–1.6 cm maximum shell length). In the first stage, the predator was given each limpet size class separately. In the second stage, the fish was given a choice between the two classes. Lipophrys pholis was shown to have a preference for the large size class (1.5–1.6 cm). The average number of limpets consumed by the shanny was examined for the duration of one high‐tide typical of the central region of Portugal (≈ 4 h). On average, approximately five limpets (up to an eight limpet maximum) were consumed. The present study shows that L. pholis has a feeding preference based on limpet size, which suggests that the limpet population structure and intra‐ and inter‐specific interactions may be influenced by the shanny predation.     

渔山列岛潮间带底栖海藻生态的初步研究

本文根据１９８７年１１月至１９８９年５月渔山列岛（２８°５３′Ｎ，１２２°１６′Ｅ）潮间带底栖海藻调查资料，分析了该海区潮间带的海藻种类、垂直分布及生物量的季节变化规律，并将本区海藻生态特点与临近海区作了比较。     

The Influence of Primary Production Rate on the Population Dynamics of Patella granulans, an Intertidal Limpet

Abstract. The production rates of intertidal algae at seven study sites in the Saklanha Bay area. South Africa, were measured monthly for 15 months. Algae grew rapidly and formed extensive, permanent mats on shores that were enriched with nutrients from the dissolved guano of seabirds. The most significant correlate of limpet (Patella granulans) growth was the rate of algal production; more rapid limpet growth on nutrient-rich shores, combined with the effects of predation by African Black Oystercatchers Haematopus moquini on limpets, led to differences in the size structures and life-history patterns of populations of limpets on enriched and unenricheci shores. The rate of primary production affected relationships between intertidal organisms at all trophic levels and influenced patterns of organization within the community.     

南极菲尔德斯半岛潮间带南极帽贝的种群生态学研究──夏季种群数量变化和垂直分布

于1994年12月—1995年3月（南极夏季）期间,对南极菲尔德斯半岛卵石滩、岩石滩潮间带南极帽贝的种群数量、垂直分布进行了定点、定时、定量的调查和观察。结果表明,南极帽贝的种群数量有明显下降,分别仅为起始数量的35％和52％。卵石滩潮间带的帽贝分布于中潮区及低潮区,尤其是低潮区,且有随季节（冬季来临）向潮下带移动的趋势。岩石滩潮间带的帽贝具有类似的垂直分布特征,但其在分布带上的发生频次有很大差异,呈波动状态。在垂直岩面上,帽贝数量在低潮区的底部更为集中。讨论了导致数量变化、垂直分布的可能原因。今后有必要深入研究种群数量的时空动态及其调控机理。     

Intertidal Invertebrate and Algal Communities on the Rocky Shores of the Bay of Morbihan, Kerguelen (South Indian Ocean)

Abstract. Both the emergent surfaces and tide pools of the rocky intertidal shores of the Bay of Morbihan, Kerguelen are depauperate in number of macroinvertebrate and macroalgal species. Diversity (H') was high and similar for macroinvertebrates in tide pools from the high to low intertidal and on the emergent surface exposed at extreme low-tide when calculated in terms of numbers of individuals. H' was lower when calculated in terms of energy and twice as high for the tide pool in the high intertidal than the lower tide-pools and the emergent surface. H' for macroalgae was 0 in the highest tide-pool and highest in the lower tide-pools. The density/species-rank curves for the macroinvertebrates and the macroalgae are logarithmic but vary in linearity. Algal biomass was 37 % of the macroinvertebrate biomass on the emergent surface at the extreme low-tide, but 106% in the highest tide-pool. Twenty-three months after denudation of the tide pools, the ratios of total densities of the macroinvertebrates (ind m^-2) to the original densities were 48 % for the pool in the high intertidal, 25 % for the middle tide-pool, and 4 % for the pool in the low intertidal. The diversity indexes for the macroinvertebrates were similar to the original ones. Recolonization at Kerguelen is slow and shows an intertidal gradient. The composition of the rocky intertidal community at Kerguelen results from the rigorous physical environment and the small number and functional types of species. In the absence of major predators on macroinvertebrates and of herbivores on macroalgae, interaction among the species present seems to be competitive in nature.     

Comparative study on the fauna composition of intertidal invertebrates between natural and artificial substrata in the northeastern coast of Jeju Island

This study was carried out to learn about differences in the sessile macrobenthic fauna communities between the artificial and natural habitats. There were some differences in terms of species composition and dominant species and community structure between two habitat types. The dominant species include Pollicipes mitella and Granuilittorina exigua in natural rocky intertidal zones; Monodonta labio confusa, Ligia exotica, Tetraclita japonica in the artificial rocky intertidal zones. Among all the species, L. exotica and T. japonica occurred only in the artificial rocky intertidal zone. The results of cluster analysis and nMDS analysis showed a distinct difference in community structure between artificial and natural rocky intertidal zones. The fauna in the natural rocky intertidal zones were similar to each other and the fauna in the artificial rocky intertidal zones were divided depending on the slope of the substratum. In the case of a sloping tetrapod, M. labio confusa and P. mitella were dominant, but at the vertical artificial seawall, Cellana nigrolineata, L. exotica T. japonica were dominant. The analysis of the species presented in natural and artificial rocky intertidal areas showed the exclusive presence of 10 species on natural rocks and 12 species on artificial rocks. The species in the natural rocky intertidal area included mobile gastropods and cnidarians (i.e. rock anemones), and the species in the artificial rocky intertidal area mostly included non-mobile attached animals. The artificial novel structure seems to contribute to increasing the heterogeneity of habitats for marine invertebrate species and an increase the species diversity in rocky coastal areas.     

Reproduction in the intertidal limpet Cellana ornata in southern New Zealand

The reproductive cycle of the abundant intertidal limpet Cellana ornata (Dillwyn 1817) was examined over 19 months, covering two breeding periods, on a rocky intertidal platform in southern New Zealand. A gonad index was calculated, and histological sections were used to count the numbers of mature and immature eggs present. Fecundity was estimated using counts of eggs before and after spawning. To determine any variation between sites, the gonad index of limpets at a second site dominated by boulders was examined over 6 months during the second breeding period. C. ornata had a single spawning period annually during summer, with greatest gonad sizes in January‐February. There were significant differences in peak gonad indices between two breeding seasons on the platform. Within the second breeding period, both the timing and magnitude of peak gonad development differed between sites, with lower reproductive output at the boulder site. Fecundity increased with increasing size, but individuals are probably capable of reproducing after their first year on the shore. The life history of this species is discussed in comparison to other limpets in New Zealand.     

Evidence of the restricted gene flow within a small spatial scale in the Japanese common intertidal goby Chaenogobius annularis

Elucidating the scale of gene flow among populations is an important challenge for understanding the ecological dynamics and local adaptation of marine organisms. We assessed whether gene flow is restricted even at a small spatial scale in the Japanese common intertidal goby Chaenogobius annularis, using highly polymorphic DNA markers, involving the mitochondrial DNA (mtDNA) control region and 15 microsatellite DNA (msDNA), because past ecological studies have suggested low dispersal ability for rocky intertidal fishes. We found significant heterogeneities between four neighboring local populations by both mtDNA and msDNA analyses. In addition, no genetic heterogeneity was detected by either method across generations within a population; it was considered that such genetic differentiation is retained across generations and that the gene flow of this species is restricted to within a radius of a few kilometers. This is the first report showing a clear genetic subdivision in rocky intertidal fish.     

舟山岩相潮间带动物群落结构的研究

本文应用数理统计方法研究了舟山海区岩岸潮间带中26个测站的春季动物群落结构。根据26个站的位置分为近岸区、近外海区和外海区3个区域。各站均以软体动物和甲壳动物为群落主要组成成分,群落种类组成数从近岸到外海呈增长趋势,且优势种亦从低盐种类向高盐种类演替。近岸区群落主要优势种为短滨螺Littorina brevicula、粗糙滨螺L.scabra、僧帽牡蛎Ostrea cucullata、白脊藤壶Balanus albicostatus等;近外海区为短滨螺、粒结节滨螺Nodilittorinaexigua、僧帽牡蛎、鳞笠藤壶Tetraclita squamosa squamosa、白脊藤壶等;外海区为粒结节滨螺,疣荔枝螺Purpura clavigera、条纹隔贻贝Septifer virgatus、日本笠藤壶T.japonica及藻类等。但群落个体密度和生物量从近岸到外海呈减少趋势。从近岸到外海,群落的Shannon-Wiener多样性指数H和Pielou均匀度J均增加,而McNaughton优势度D减少。群落结构从近岸到外海渐趋复杂。但整体上,舟山海区岩岸春季动物群落结构是比较简单的(绝大多数断面H值小于2.50,J值小于0.5。而D值大于0.6)。近外海区的群落结构比较相似于外海区的群落。根据平均聚类分析,这26个群落可以分为三个生态类型,即隐蔽性岩岸群落,半隐蔽性岩岸群落及开敞性岩岸群落。     

The Dynamics of an Introduced: Balanus glandula Population in the Southwestern Atlantic Rocky Shores. The Consequences on the Intertidal Community*

Abstract. This paper deals with the population dynamics of the introduced barnacle Balanus glandula in a port shelter and a rocky shore exposed of a southwestern Atlantic area. Replicated areas in both zones were denuded monthly and censused in both the high intertidal and the upper mid intertidal zone. The settlement pattern. recruitment, mortality and growth of B. glandula and a comparative successional pattern in both areas were recorded. Recruitment began in winter, i.e., July in the port and August in the rocky shore. In the port, green algae dominate up to a final community of Balanus glandula all along the intertidal, while in rocky shores the red encrusting alga Hildenbrandia lecanellieri establishes a cover that is replaced by the mytilid Brachidontes rodriguezi in the mid intertidal and by B. glandula in the high intertidal and upper mid intertidal. B. glandula densities were greater in the upper mid intertidal 19 600 and 5050 indiv. · m^-2 in the port and rocky shore, respectively than in the high intertidal 13600 and 1100 indiv.· m^-2, respectively. Mortality was greater in the port up to 62%, but heavy settlement allows a final density 4 times greater than in eulittoral rocky shores and 10 times greater than in the high intertidal. The winter reproduction of Balanus glandula, the absence of predators, the neutral or beneficial effect of algae. with spatial and temporal partitioning of substrate allows it to successfully outcompete mussels and other barnacle species from the intertidal community of both sheltered and exposed areas.     

Comparing quality of estuarine and nearshore intertidal habitats for Carcinus maenas

Estuarine and nearshore marine areas are vital habitats for several fish and benthic invertebrates. The shore crab Carcinus maenas (Crustacea: Brachyura: Portunidae) inhabits a variety of coastal, estuarine and lagoon habitats. At low tide, habitat structural complexity may be most important for crabs in the intertidal, providing refuge from predation and desiccation. The quality of different vegetated and nonvegetated estuarine and rocky shore habitats in SW Portugal and SW England was evaluated for intertidal C. maenas populations. We estimated population density, size–structure, and potential growth (RNA/DNA ratios) to investigate habitat quality. Vegetated estuarine habitats supported higher crab densities, than nonvegetated estuarine and rocky shore habitats. Investigation of population size–structure revealed that all habitats seem important recruitment and nursery areas although estuarine habitats in SW Portugal appeared to support higher densities of new recruits than equivalent habitats in SW England. Significant variation was found in RNA/DNA ratios among habitats. Ratios were highest in the rocky shore suggesting a high quality habitat where growth potential is high. We speculate that competition from other top-predators (Pachygrapsus spp.) rather than low habitat quality may limit the occurrence of C. maenas in intertidal rocky shore habitats in SW Portugal. In estuarine environments RNA/DNA ratios were significantly higher in the vegetated than in the nonvegetated estuarine habitats in SW Portugal but not in SW England, suggesting geographic differences in the extent to which highly structure habitats represent high quality. Our results challenge the current paradigm that structured habitats are necessarily those of higher quality for C. maenas.     

南麂列岛海洋自然保护区潮间带软体动物生态研究

本研究结果表明，共鉴定出软体动物１４３种，其中１８种为该区域首次记录。根据种类相似性指数，将其分成５个生态群落：即开敞岩礁群落，隐蔽岩礁群落，巨砾群落，泥滩群落，沙滩群落。文中对各群落的种类组成、数量分布、季节变化及多样性指数等作了分析；同时对影响软体动物生态分布的潮汐、波浪、底质类型和生物因子等作了探讨。     

北麂列岛岩相潮间带蔓足类的种类及数量分布

根据 1 997年 7月至 1 998年 4月在浙江北麂列岛岩相潮间带采集的样品 ,共鉴定出蔓足类 9种 ,隶属于 5科 7属 ,以东、南海及日本海南部的暖水性种占优势。描述了蔓足类的种类组成、数量分布和季节变化 ,讨论了盐度、潮区和浪击作用对岩相潮间带蔓足类分布的影响。     

Effects of the MV Rena oil spill on intertidal rocky reefs in the Bay of Plenty,New Zealand

In the weeks following the 2011 Rena oil spill, a series of surveys was initiated on eight rocky intertidal reefs to describe the distribution of oil and to assess the impacts of oil on ecological communities. Consistent but relatively low cover of oil occurred at two sites (Mt Maunganui and Moturiki). The area covered by oil had decreased by c. 90% after 5 months due to natural weathering processes. There were immediate effects of oil fouling on the mussel Limnoperna pulex and its associated fauna, with reductions in the number of mussels and infaunal taxonomic richness. However, no ecological effects on any of the communities were detectable after 1 month. Overall, the ecological effects of the Rena oil spill on rocky shore intertidal communities were small and not long-lasting, but we stress that this does not consider potential sublethal effects and their consequences on organisms.     

Historical demography of southern African patellid limpets: congruence of population expansions,but not phylogeography

Global climatic oscillations have shaped the contemporary genetic structure of marine taxa in different ways. Previous demographic studies have indicated that various intertidal marine species display genetic signatures of demographic expansion that either pre- or postdate the Last Glacial Maximum. Such expansions and the ability of species to colonise new habitats will influence their genetic structure, but the link between scales of larval dispersal and the strength of phylogeographic structure is not always clear. We analysed a fragment of the mitochondrial COI gene of 11 sympatric species of intertidal southern African patellid limpets to investigate how ancient oceanographic dynamics have shaped and maintained their contemporary spatial genetic variation. Our data show that the patellid limpets investigated display congruent evidence of spatial expansion during the Late Pleistocene or Early Holocene, which corresponds with the establishment of the contemporary southern African shoreline. We argue that closely related and co-distributed southern African intertidal invertebrates responded to ancient climatic oscillations as a cohesive group. In contrast, contemporary oceanographic circulation has shaped the phylogeographic patterns of these limpets in different ways. We show close relationships between phylogeography and biogeography for some species, but not for others, despite the similarities in their life histories and exposure to the same climatic changes.     

厦门地区潮间带蟹类的种类组成与分布

本文根据厦门地区三个岛屿潮间带调查所获的资料，研究了蟹类的种类组成与分布，并应用多样性指数分析了蟹类的结构特征。经鉴定的蟹类有１４种５５属９１种，其中软相５７种，岩相４４种。软相的蟹类组成与岩相的明显不同。     

浙江苍南无居民海岛岩相潮间带生物群落多样性研究

为了解浙江苍南海域无居民海岛岩相潮间带生物群落组成与结构,于2019年3月对该海域内11个无居民海岛进行了潮间带生物调查,对采集到的样品进行鉴定,并计算了栖息密度、生物量和生物多样性指数。11个无居民海岛共鉴定出58种潮间带生物,平均栖息密度和平均生物量分别为857±205 ind/m2和2 847.83±1 032.50 g/m2,各断面的Shannon-Wiener多样性指数H′、Pielou均匀度指数J和Margalef丰富度指数D范围分别为1.07~1.61, 0.66~0.83和0.54~1.30。与大陆沿岸潮间带相比,无居民海岛生态系统独特,拥有更多的生物资源,具有重要的生态价值,需要重视并加强保护。     

Biofilm: A crucial factor affecting the settlement of seaweed on intertidal rocky surfaces

We hypothesized that the presence of biofilm accelerated the settlement of dominant seaweed species and maintained high levels of species richness by regulating the blooming of particular species on an intertidal rocky shore. The coverage and species richness of macroalgae on sterile and cleared substrates (225 cm²) were measured to investigate the effects of biofilm on the settlement of macroalgae in intertidal zones at Noryang, Songmoon, and Sangnam in Gawngyang Bay on the southern coast of the Korean peninsula. Green algae coverage on cleared substrates was significantly higher than that on sterile substrates at both Noryang and Songmoon during the study period. This suggests that the presence of biofilm enhances the settlement of green algae by providing various habitat structures and, consequently, may lead to serious ‘green tide’ events. However, the coverage of algae other than green algae and algal species richness on cleared substrates remained high at Sangnam during the experimental period. Biofilm facilitated the settlement of macroalgae and inhibited the blooming of specific algae by inducing inter-specific space competition. Therefore, biofilm plays an important role on seaweed assemblages on intertidal rocky shores by accelerating the settlement of seaweed.     

Small-scale variations in mussel (Mytilus spp.) dynamics and local production

A mussel bed was sampled monthly at four intertidal levels (mid: 2.15; mid-low: 1.65; low: 1.2 and sublittoral fringe: 0.7 m from chart datum) from July 1979 to July 1980 at Pointe-Mitis in the St. Lawrence estuary. A strong spring reduction of abundance (both in density and biomass) suggested that the mussel bed was being degraded. Community perturbation was attributed to ice scour. Partial reestablishment of the mussel bed (all age classes) was observed during late spring and early summer and occurred mainly at the mid-low intertidal level. Changes in the size structure of the mussel bed with level suggest that the annual windstorm regime may be an important factor in the dynamics of the bed. Mean body mass decreased at the three lower shore levels but increased at the highest shore level. Overall, net secondary production (assessed by the increment-summation method) was negative due to the decrease in mean body mass. Annual production rates (kJ m⁻² y⁻¹) from the mid intertidal level to the sublittoral fringe were 1130, − 4072, − 4013 and − 3258, respectively, while P/B ratios (y⁻¹) were 0.17, − 0.69, − 0.50 and − 0.45. The calculated production and the productivity (potential production) are compared and used to provide insight into the condition of the mussel bed.     

Abundance of biofilm on intertidal rocky shores: Can trampling by humans be a negative influence?

Trampling by human visitors to rocky shores is a known stressor on macroorganisms. However, the effects of trampling on rocky intertidal biofilm, a complex association of microorganisms of ecological importance in coastal communities, have not been quantified. We evaluated the impact of trampling frequency and intensity on total biomass of epilithic microalgae on intertidal rocky shores in the southeast of Brazil. There was a trend of increase in the variability of biomass of biofilm in function of intensity of trampling, but no significant effects emerged among trampling treatments. The low influence of trampling on biofilm might be a result of the small dimensions of the organisms coupled with their natural resilience and roughness of the substrate; the former preventing the removal of biofilm layers by shoes and facilitating their quick recovery. Our results provide insights for management and conservation of coastal ecosystems revealing a weaker impact of trampling on biofilm than that reported on macroorganisms.