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1.
The mobile fauna associated with two sympatric kelp species with different holdfast morphology (Saccorhiza polyschides and Laminaria hyperborea) was compared to test for differences in the assemblage structure of holdfast-associated mobile epifauna. A total of 24,140
epifaunal individuals were counted from 30 holdfasts of each kelp species. Overall epifaunal abundances exceeded faunal abundances
previously reported from holdfasts of other kelps. Three taxonomic groups, Amphipoda, Mollusca, and Polychaeta, accounted
for ca. 85% of all individuals. Total abundances increased with the amount of habitat available, quantified either as the
volume or the area provided by the holdfasts. The multivariate structure of the epifaunal assemblage did not differ between
holdfasts of the two kelp species. However, epifaunal assemblages responded differentially to the habitat attributes provided
by each type of kelp holdfast: multivariate variation in the assemblage structure of epifauna was mostly explained by holdfast
area and volume for L. hyperborea, and by the surface-to-volume ratio for S. polyschides holdfasts. Therefore, the physical attributes of biogenic habitats, here kelp holdfasts that better predict patterns in the
assemblage structure of associated fauna can differ according to their different physical morphology, even though the overall
assemblage structure of associated fauna was similar. 相似文献
2.
Maria Włodarska-Kowalczuk Piotr Kukliński Marta Ronowicz Joanna Legeżyńska Sławomira Gromisz 《Polar Biology》2009,32(6):897-905
Kelp beds support diverse and productive benthic coastal ecosystems and are often perceived as cold water analogs of tropical
coral reefs, yet the levels of species richness in polar regions have remained largely unexplored. The present study aims
to assess the magnitude of macrozoobenthic species richness associated with the macroalgae in an Arctic kelp forest. The study
was conducted in Hornsund, a high latitude Arctic fjord off west Spitsbergen (76–77°N). A total of 403 samples (i.e., individual
algae) were collected by scuba divers at three sites located along the fjord axis at varying depths (5–10 m). The most common
invertebrate species and the sample species richness (mean 11.5 species per sample) were consistent among the most common
algal species (Laminaria digitata, Saccharina latissima,
Alaria esculenta, Desmarestia aculeta, Odonthalia dentata, Phycodrys rubens). Fauna associated with overstory kelps was concentrated on the holdfasts. A total of 208 species were identified; Bryozoa,
Polychaeta and Hydrozoa yielded the highest numbers of species (70, 52 and 37, respectively). The non-parametric Chao2 estimator of true species richness gave an estimate of 259 species (with 95% confidence intervals from 234 to 308). Despite
the high sampling effort, the total species richness was not captured. This may stem from the high level of rarity within
the fauna associated with kelps; 38% of the species occurred only in one or two samples. The studied fauna was much less diverse
than similar assemblages surveyed at lower latitudes. The high numbers of species and the common occurrence of colonial forms
(Bryozoa, Hydrozoa) in the current study show that these taxa cannot be omitted in macrobenthic diversity surveys performed
within kelp habitats. 相似文献
3.
The polychaete community associated with holdfasts of the brown alga Himantothallus grandifolius in Admiralty Bay has been studied. It is the first study of its kind in this area and only the second in the Antarctic. Samples
were collected in the summer season of 1979/1980 from a depth range of 10–75 m. Seventy-eight species were found on 19 holdfasts.
The community was dominated by Brania rhopalophora and Neanthes kerguelensis. Analysis of similarity showed that polychaete fauna associated with this habitat did not show any partitioning related to
depth. Regression analysis showed that densities of both species and individuals decreased with increased holdfast volume.
A positive correlation was found between the number of individuals and holdfast volume. Polychaetes from 10 feeding guilds
were found with dominance of macrophagous motile herbivores and sessile filter feeders. The complex habitat provided by holdfasts
is a shelter for a rich polychaete fauna and may function as important protection from disturbance in the shallow areas of
Admiralty Bay. 相似文献
4.
Robert K. Howard 《Environmental Biology of Fishes》1989,24(2):93-104
Synopsis Extensive limestone reefs are a characteristic feature of much of the coastline of Western Australia, and potentially represent a major habitat feature influencing the structure of the coastal fish community. The structure and temporal dynamics of the fish fauna and its relationships to nearshore patch reefs and surrounding habitat near Dongara, Western Australia, were examined using (1) diel gill-netting and (2) quantitative rotenone sampling of enclosed areas of substratum. Long-term and day-to-day variability of the fauna was low. Dominant species of gill-net collections were either associated with reefs or occurred in similar abundances at both reefs and surrounding sand/seagrass flats. The overall abundance, number of species and biomass of netted fishes was higher around reefs. Rotenone collections of the more sedentary species showed a similar pattern, but suggested, however, that a simple reef versus surrounding sand and seagrass habitat comparison is complicated by the canopy-forming seagrass Amphibolis that occurs on reef tops. Time of day had an important effect on overall fish abundance and number of species, with peaks occurring at crepuscular periods. This reflected dusk and dawn activity peaks of a dominant species rather than overlapping activities of many diurnal and nocturnal species. Diel switches between reef-edge habitat and surrounding sand/seagrass flats were uncommon despite expectations (based on literature examples) that patch reefs would function primarily as sheltering habitats and surrounding non-reef areas act as foraging habitat. High catches at reef-edge sites suggest that the majority of fishes forage on or near limestone patch reefs. Fish densities of around 0.8 individuals per m-2 of bottom on these Western Australian reefs are relatively high in comparison to visual census estimates obtained for temperate reef systems in South Australia and New Zealand, but similar to those obtained using comparable netting methods in temperate Australian seagrass systems. 相似文献
5.
Carlos Ríos Wolf E. Arntz Dieter Gerdes Erika Mutschke Américo Montiel 《Polar Biology》2007,31(1):89-100
Macrocystis pyrifera (L.) C. Agardh is a characteristic macroalga in the Magellan region covering almost 30% of the shallow coastal waters. The
focus of this study was to analyse the spatial and seasonal patterns in macrofauna communities associated to the holdfasts
of Macrocystis pyrifera at two study sites in the Straits of Magellan, South Chile. In total, 114 species from 10 major taxa were isolated from the
holdfasts. MDS clearly separated the holdfast fauna collected in different seasons, with autumn and winter collections being
richer in terms of species richness and abundance as compared to the spring and summer situation. MDS also clearly separated
the holdfast associated faunas of the two study sites, Bahía Laredo and Fuerte Bulnes. The community structure and species
composition of the associated macro-invertebrates and vertebrates appeared rather heterogeneous, probably due to the extremely
heterogeneous environmental conditions along the entire coastline of the Subantarctic Magellan region. 相似文献
6.
Yu. Ya. Latypov 《Russian Journal of Marine Biology》2009,35(6):454-462
New data on the species composition and distribution of reef-building corals on some reefs of the Seychelles Islands are presented.
The study revealed 236 species belonging to 68 genera, which exceeds the well-known values of scleractinian species composition
in this region by almost two times. Representatives of the families Acroporidae, Poritidae, and Faviidae dominated. Settlements
of the blue coral Heliopora coerulea and the hydroid Millepora dichotoma were fairly numerous and in aggregate covered up to 40% of the substratum. In its species composition, the coral fauna of
the Seychelles reefs makes a single unit with the Indo-Pacific tropical fauna. 相似文献
7.
In general, biodiversity and species richness follow the latitudinal diversity gradient and decrease from the tropics towards
the poles. Exceptions have however been recorded, as for deep coldwater coral reefs at high latitudes, which comprise biodiversity
hotspots. Here we assess and characterise the high-latitude (69°N) species richness and diversity of a local shallow-water
fauna associated with small calcareous aggregations of a serpulid polychaete. A dense and very species rich fauna was recorded
within aggregations of Filograna implexa Berkeley, 1828. Totally 4663 individuals belonging to 99 species (61 solitary, 38 colonial) were recorded in a total aggregation
volume of only 4.4 l covering an area less than 0.05 m2 of a wreck situated in a tidal stream in North Norway. The number of species within each aggregation was positively related
to its size, indicating that the high species diversity may be due to structural heterogeneity, which increase with aggregation
size and probably creates new microhabitats and protect against predation. We present a species list including abundance and
biomass, pin-point common species and describe a method for sampling such faunas associated with calcareous structures. 相似文献
8.
Kenyan coral reef-associated gastropod assemblages: distribution and diversity patterns 总被引:1,自引:0,他引:1
T. R. McClanahan 《Coral reefs (Online)》1990,9(2):63-74
A survey of Kenya's shallow water (<2 m) coral reef-associated prosobranch fauna was undertaken to determine patterns of distribution, density, diversity and species richness, and the possible role of other reef fauna and human utilization on these patterns. The sample assemblage of 135 species from 25 families is similar to other Indian Ocean regions with no apparent endemism or subregional faunal affinities. Species richness, determined by species-individual relationships, has been reduced by approximately 45% since the Pleistocene. Northern Kenya, typified by small coral islands experiencing river and estuarine discharges had low densities and species richness and high species variability. This is attributable to the interrelated factors of river discharge, small reefs and reduced predator refuge. Southern Kenya's more expansive fringing reef has a denser and richer fauna but appears less species rich than Tanzania. Variation within reefs suggests similarities in diversity between reef lagoons, flats and edges, but lagoons had lower densities than reef flat or edge sites. This is attributable to greater predation rates within lagoons. Species composition between reef locations was variable but differed for comparisons between reef lagoons and reef flats. The population densities of thirty commercially collected species were compared between shelled and unshelled reefs. Only two commercial strombids, Lambis truncata and L. chiragra, had lower densities within shelled compared to unshelled reefs. Within six southern Kenvan reef lagoons, total gastropod densities were negatively correlated with the Balistidae (triggerfish) and total fish densities and positively with sea urchin densities. The removal of balistids through fishing appears to lead to co-occurring population increases in gastropod and sea urchin populations which, in most instances, appears to negate the effect of shell collecting. 相似文献
9.
Visual censuses of tropical fish aggregations on artificial reefs: slate versus video recording techniques 总被引:1,自引:0,他引:1
Emmanuel Tessier Pascale Chabanet Karine Pothin Marc Soria 《Journal of experimental marine biology and ecology》2005,315(1):17-30
Artificial coastal reefs were initially installed off Reunion Island (SW Indian Ocean) in order to attract and catch small pelagic fish of economic importance for the local fishery. These artificial reefs also attract a high density of juvenile coral reef fish, especially after recruitment. Because of high species richness and density, a suitable method of evaluating diversity and abundance in such assemblages is needed. An experiment was conducted in situ for 1 year in order to test which of the two visual techniques, slate or video recording, would be the most suitable for sampling artificial reefs. For the quantitative study, a rope framework (four belt transects each measuring 24×3 m) was used to ease the movement of the divers. To avoid bias due to time variations, the study was conducted under limited time in situ. The advantages and disadvantages of the two techniques regarding the accuracy of qualitative and quantitative results are discussed. The qualitative study results show that the slate technique is the most accurate one for determining species richness. In the quantitative study, factors such as species characteristics (ecological type), attractiveness (relationship between fish and diver) and abundance of fish communities around the artificial reefs appear to influence our results on the comparison of the two techniques. Of 13 ‘permanent’ (observed in more than 75% of dives) species, 6 returned a similar frequency of detection by slate and video (Lutjanus kasmira, Lutjanus bengalensis, Priacanthus hamrur, Chaetodon kleinii, Heniochus diphreutes, Mulloides vanicolensis); these were then selected for comparison of the techniques using quantitative data. The correlation between video and slate census results is high, but, in comparison with the slate census, the video census underestimates abundance, especially for low values. A corrected index is proposed to remedy this underestimation; it could be used for video surveys conducted on species responding well to video detection (as below). 相似文献
10.
Rodney Watkins 《Pal?ontologische Zeitschrift》1998,72(1-2):99-109
Eight species of pentamerid brachiopods, assigned toApopentamerus, Capelliniella, Kirkidium, Lissocoelina, Rhipidium, Supertrilobus andStenopentamerus, occur in stromatoporoid-coral reefs of the Silurian (Wenlockian) Racine Formation, Wisconsin and Illinois, USA. One new taxon,Rhipidium kuglitschi n.sp., is described. In contrast to level-bottom communities, where single pentamerid species occur in great numbers over large areas, pentamerids were generally rare members of the Racine reef fauna, and most species have localized distributions. An increase in diversity from one pentamerid species in the north to six species in the south correlates with a southward increase in reef size. Four morphologic groups of pentamerid species differed in the shape of the mantle cavity, which suggests different dynamics of suspension-feeding. Where two or more species are present in single reefs, co-occurrence of these groups represents a partitioning of the pentamerid niche. The relatively high diversity, local distributions, and morphologic distinctions among the Racine pentamerid fauna represent an evolutionary radiation and functional specialization of pentamerids in Wenlock reefs. 相似文献
11.
Arnold J Ammann 《Journal of experimental marine biology and ecology》2004,299(2):135-154
I evaluated a standard monitoring unit for the recruitment of reef fishes (SMURF) as a tool for ascertaining spatial and temporal patterns of reef fish recruitment in central California, USA. SMURFs consisted of a 1.0×0.35 m dia. cylinder of fine mesh plastic grid that contained a folded section of larger mesh plastic grid. SMURFs collected new recruits of 20 species of fish with 92% of the individuals collected from 10 species, mostly rockfish (genus Sebastes). An experiment varying depth of SMURFs in the water column (surface, mid-depth, or bottom) showed that surface SMURFs collected the greatest diversity of species and significantly greater abundance for eight species, with two species having significantly greater abundance on mid-depth SMURFs and three species having significantly greater abundance on bottom SMURFs. A comparison of cumulated recruitment from SMURFs that varied in sampling frequency (removal of new recruits every 1-3, 7, or 28 days) suggested that increasing the time between sampling caused a significant decrease in recruitment estimates for some species but not for others. To determine how well temporal patterns of recruitment to SMURFs reflected patterns to nearby reefs, I compared within season temporal patterns of recruitment to SMURFs with that at nearby reefs, estimated by visual transect surveys conducted on scuba. Temporal patterns of recruitment to SMURFs were significantly and positively related to early recruitment on reefs for one group of benthic-algal associated rockfish species when diver surveys were lagged by 30 days (r=0.87) and for another group of canopy-algal associated rockfish species when lagged by 5 days (r=0.72). SMURFs appeared to be an effective and efficient method for indexing relative rates of delivery of competent juveniles for many temperate nearshore reef fishes. 相似文献
12.
Net pen fish farms generally enrich the surrounding waters and the underlying sediments with nutrients and organic matter, and these loadings can cause a variety of environmental problems, such as algal blooms and sediment anoxia. In this study we test the potential of biofiltration by artificial reefs for reducing the negative environmental impacts surrounding fish farms in the Gulf of Aqaba, Red Sea. Two triangular-shaped artificial reefs (reef volume 8.2 m3) constructed from porous durable polyethylene were deployed at 20 m; one below a commercial fish farm and the other 500 m west of this farm in order to monitor the colonization of these reefs by the local fauna and to determine whether the reef community can remove fish farm effluents from the water. Both reefs became rapidly colonized by a wide variety of organisms with potential for the removal of compounds released from the farms. Within the first year of this study fish abundances and the number of species reached 518–1185 individuals per reef and 25–42 species per reef. Moreover, numerous benthic algae; small sessile invertebrates (bryozoa, tunicates, bivalves, polychaetes, sponges, anemones) and large motile macrofauna (crustaceans, sea urchins, gastropods) settled on the reef surfaces. Depletion of chlorophyll a was measured in the water traversing the artificial reefs in order to assess the biofiltration capacity of the associated fauna. Chlorophyll a was significantly reduced to a level 15–35% lower than ambient concentrations. This reduction was greatest at intermediate current speeds (3–10 cm s–1), but was not influenced by current direction. The reef structures served as a successful base for colonization by natural fauna and flora, thereby boosting the local benthic biodiversity, and also served as effective biofilters of phytoplankton. 相似文献
13.
CHRISTINA FRANZÉN 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1977,10(3):219-234
Crinoid holdfasts occur throughout the Silurian sequence of Gotland, with a marked concentration to reefs and immediate reef surroundings. Four morphological groups are recognized: (1) Discoid holdfasts. (2) Cirriferous holdfasts, represented by (a) Rhizocrinus -like holdfasts, (b) large radices with stout, often branching cirri, and (c) rhizoid holdfasts, formed by a complicated net of pseudocirri. (3) Creeping stems attached to the substrate by thin strands of stereome. (4) Coiling stems. Discoid attachments, cirriferous holdfasts (types b and c) and coiling stems show little preference to substrate and adapt morphologically to conditions at hand. Rhizoid holdfasts display the greatest variation and apparently occur within many different groups of crinoids. Rhizocrinusttke holdfasts have been found only in quiet-water deposits, while creeping stems were concentrated to more turbulent environments. Coiling stems were epizoic, attached to rugose corals, bryozoans, crinoid stems and similar supports. Growth, mode of life (attached or free), settling and fixation of larvae, and relation to substrate and other organisms ate discussed. 相似文献
14.
Degraded reefs with a high abundance of macroalgae usually also have low densities of coral recruits. Few studies, however,
have examined whether these algae affect coral larval settlement. This study demonstrates, experimentally, that larvae of
the Caribbean coral Favia fragrum can settle on the green alga Halimeda opuntia even when another substrate more suitable for settlement is present. Larval settlement onto experimental substrates was quantified
under three treatments: rubble only, rubble plus plastic algal mimic, and rubble plus live H. opuntia. Similar total larval settlement was observed in all treatments. No larvae settled on the algal mimic, but total settlement
was similar on the rubble in the first two treatments, showing that the rubble alone offered sufficient substrate for high
settlement success. About half the larvae in the live algal treatment settled on H. opuntia instead of on the rubble, showing that larvae did not reject this substrate as they did the algal mimic. This result raises
the possibility that corals will settle on some macroalgae when their abundance is high. Most macroalgae, including H. opuntia, are ephemeral substrates unsuitable for post-settlement survival. Such unexpected settlement may therefore have significant
consequences for coral recruitment success on algal-dominated reefs. 相似文献
15.
Reefal units in the early to middle Miocene of Anguilla consist of small, irregular lenses of variable coral composition which developed on a shallow, isolated offshore carbonate platform. They are composed of three distinct coral biofacies (branched, mound-shaped, and platy), which are haphazardly distributed in association with inter-reef sands. These units most probably formed as patch reefs across a broad, shallow area that was exposed to moderate energy conditions and periodically affected by storms. No evidence supports the existence of a more extensive barrier reef system. Comparisons with Oligocene and Mio-Pliocene reefs suggest that during the early to middle Miocene, Caribbean reefs were generally smaller in size (<100 m3) and lower in diversity (21 species in Anguilla, 42 species in total across the Caribbean) than Caribbean reefs during the late Oligocene or during the ate Miocene to early Pliocene (71 species in the Dominican Republic, 80 species total across the Caribbean). The early to middle Miocene Caribbean reef coral fauna was dominated by nine widespread species that occur in deposits of similar age in both Anguilla and Panama. More than half of the fauna consisted of Oligocene relicts. Of the 21 genera that first appeared in the Caribbean during Miocene time, 14 had first occurrences after the middle Miocene, as barrier reef systems became more prevalent across the central Caribbean. 相似文献
16.
von Bertalanffy curves were used to describe the nonlinear relationship between assemblages inhabiting holdfasts of the kelp Ecklonia radiata and the volume of the holdfast. This was done using nonlinear canonical analyses of principal coordinates (NCAP). The volume of the holdfast is a proxy for the age of the plant and, thus, the canonical axis is a proxy for succession in the marine invertebrate community inhabiting the holdfast. Analyses were done at several different taxonomic resolutions on the basis of various dissimilarity measures. Assemblages in relatively large holdfasts demonstrated ongoing variation in community structure with increasing volume when the dissimilarity used was independent of sample size. Smaller holdfasts had proportionately greater abundances of ophiuroids and encrusting organisms (bryozoans, sponges, ascidians), while larger holdfasts were characterised by proportionately greater abundances of crustaceans, polychaetes and molluscs. Such linear and nonlinear multivariate models may be applied to analyse system-level responses to the growth of many habitat-forming organisms, such as sponges, coral reefs, coralline algal turf or forest canopies. 相似文献
17.
Allozyme variation at six polymorphic loci was examined in 10 populations of Tridacna maxima from reefs in the Western Coral Sea, to test whether patterns of relatedness previously reported for foraminiferan populations reflected a fundamental structuring of the fauna in the region. Genetic distances (Nei's D) among populations of T. maxima ranged from 0–0.065 and increased with increasing geographical separation. No significant differences in gene frequencies were observed among populations within two groups of reefs identified by cluster analysis: the Great Barrier Reef (GBR), and among the offshore reefs excluding Lihou and Osprey. Significant genetic differences among these groups and the outliers Lihou and Osprey were consistent with the greater geographical separation of populations between areas than within areas. There was no evidence of differentiation along a north-south axis as reported for the foraminiferan Marginopora vertebralis, nor did populations from offshore reefs on the Queensland Plateau form a well-defined group that was genetically distinct from the GBR. The patterns observed for M. vertebralis do not appear to reflect a fundamental structuring of biota in the region. The differences in the pattern of genetic variation for M. vertebralis as compared with those for T. maxima may be due to several differences in the biological characteristics of the two species. The time of breeding in particular may influence the extent to which the divergence of the East Australian Current restricts larval dispersal among reefs in the central Queensland Plateau. 相似文献
18.
Sympagic macro-fauna from multiyear sea-ice near Svalbard 总被引:6,自引:6,他引:0
Summary The object of the present investigation was to map the distribution and abundance of sympagic fauna (= ice fauna) (>350 m) within the perennial sea ice zone near Svalbard and to study relations between the sympagic fauna and the age and history of its ice substrate. The sampling took place in July/August 1986 and September 1988 using SCUBA-operated sampling gear (suction samplers, plankton nets with especially designed frames for sampling at the sea-ice/seawater interface, and underwater cameras). The amphipods Apherusa glacialis, Onisimus sp., and Gammarus wilkitzkii were the most conspicuous sympagic species both years. Scattered individuals of the amphipods Gammaracanthus loricatus, Weyprechtia penguis and the polychaete Harmathoinae indet. were also recorded. A. glacialis was the most numerous and contributed near 65% of the collected specimens in both years, with a maximum density exceeding 2000 individuals/m2. However, G. wilkitzkii was on average larger, and contributed most to the biomass (1986: 80%; 1988: 77%). The average biomass of sympagic fauna in 1986 and 1988 was estimated to be 4.7 g/m2 and 8.3 g/m2 respectively. Biomass values reported here are ten to hundred times higher than what is found within the seasonal sea ice zone. Autochthonous sympagic species, like A. glacialis, Onisimus sp. and G. wilkitzkii, have a permanent association with ice. The seasonal sea ice zone will thus have to be recolonized every year resulting in lower densities compared to multiyear ice. It is suggested that the speed of the ice leaving the Polar Basin through the Fram Strait is too high for the sympagic fauna to remain its position in the sea ice zone. The result is an annual loss in the order of 7*105 tons of sympagic fauna from the perennial sea ice zone. 相似文献
19.
《African Journal of Aquatic Science》2013,38(2):133-142
Benthic macroinvertebrates were sampled and environmental variables measured at Langeni Forest and Kambi Valley, two sites of varying degrees of human impact in the upper Mthatha River, South Africa, in 2010–2011. Four species, Simulium adersi Pomeroy, Baetis harrisoni Barnard, Pseudocloeon sp. and Tricorythus sp., occurred at all site sampling units. Specimen counts increased from the rainy months of January to April/May, and higher numbers of individuals occurred at Langeni. Species occurrences per site were directly or indirectly affected by season, substrate and habitat heterogeneity. Canonical correspondence analysis results showed that conductivity, pH, flow, substrate and marginal vegetation were important in determining species distribution patterns. Both rare/habitat-restricted and common/widespread benthic macroinvertebrates identified in this study can be used as indicators for assessing the ecological integrity of the Mthatha River. Habitat management along the river should aim at preserving indigenous vegetation, especially during the summer season when habitat requirements are optimal for growth stages of most benthic macroinvertebrate fauna. The practicality of using species-level surveys on a routine basis can be challenging, given the lack of taxonomic expertise and time constraints. It might be advisable to select a few indicator species and to monitor them as surrogates for the whole community. 相似文献
20.
Ecological effects of harvesting Lessonia (Laminariales,Phaeophyta) in central Chile 总被引:1,自引:1,他引:0
Lessonia nigrescens and L. trabeculata are economically important canopy-forming kelps in Chile. Experimental harvesting of stipes above the first dichotomy reduces stipe movement and inter-stipe friction, allowing the development of a heavy epiphytic load and increased grazing. Complete stipe removal leads to holdfast death as neither species is able to simultaneously regenerate all stipes. The invertebrate fauna inside the holdfast does not respond to upper canopy changes, but mortality does occur in partial or complete plant removals. Kelp removal also affects inter-plant distances, results in increased access of grazers to the outside and inside of kelp holdfasts, reduces recruitment of other algal species, and modifies the morphology of L. trabeculata such that the plants become more susceptible to removal by water movement. 相似文献