scholarly journals REDE ECOLÓGICA DOS GASTRÓPODES ASSOCIADOS AO BANCO DE ALGAS DA PRAIA DA RIBANCEIRA, SANTA CATARINA, BRASIL

2021 ◽  
Vol 25 (01) ◽  
pp. 47-58
Author(s):  
Renato Colares ◽  
◽  
Thuany Machado ◽  
Filipe Machado Patel ◽  
Natália da Silva Brunelli ◽  
...  
Keyword(s):  
Structural Complexity ◽  
Niche Overlap ◽  
Multivariate Techniques ◽  
Rocky Shores ◽  
Wet Season ◽  
Santa Catarina ◽  
Tidal Zone ◽  
Intertidal Zones ◽  
Key Species ◽  
Sargassum Cymosum

Among the rocky shores’ biota, the networks of interaction between macroalgae and associated organisms, especially gastropods, stand out. In order to contribute to the understanding of the ecology of rocky shores, this study aims to evaluate the relation between macroalgae and associated gastropods in Ribanceira Beach, Imbituba, Santa Catarina, Brazil. The survey of algae samples took place in a wet season, using 20 cm x 20 cm quadrants, allocated in 18 transects distributed equally in the infra and mesolittoral zones, with five points each. In the laboratory, algae were screened and associated gastropods identified. Concepts of network theory were applied for a better understanding of interactions among organisms, where connectance descriptors, niche overlap and centrality index for each species were calculated. Multivariate techniques were used to assess the significance of intertidal zones, morphofunctional group and other variables in the composition of the associated gastropods. The sampling resulted in a total of 1.466 gastropods, distributed in 14 species and nine families. In relation to the macroalgae, 14 species were identified, with seven presenting associated gastropods. The ecological network showed low connectance and niche overlap for both levels (gastropods and macroalgae), suggesting the existence of many specific interactions. The centrality values highlighted Eulithidium affine (C.B. Adams, 1850) and Sargassum cymosum C. Agardh as key species in the studied network. The mass and morphofunctional group of the macroalgae sampled showed influence in the composition of the associated community. Cortical algae, especially S. cymosum, stood out with high levels of species richness and species density of associated gastropods, suggesting importance in the structural complexity of macroalgae for gastropods. The non-significant effect of the tidal zone for the gastropod composition was highlighted, suggesting that the nesting and foraging stability provided by the macroalgae allows the same gastropod species to occur in both infralittoral and mesolittoral zones.

scholarly journals The diversity of marine invertebrate macrofauna in selected rocky intertidal zones of Matara, Sri Lanka

2021 ◽  
pp. 15-21
Author(s):  
M.P. Wickramasinghe ◽  
◽  
K.A.M. Sudarshani ◽  
H.C.E. Wegiriya ◽  
Keyword(s):  
Marine Invertebrate ◽  
High Tide ◽  
Similarity Index ◽  
Abundant Species ◽  
Rocky Intertidal ◽  
Line Transect ◽  
Rocky Shores ◽  
Tidal Zone ◽  
Intertidal Zones ◽  
Macroinvertebrate Fauna

The present study was conducted in intertidal rocky shores at Wellamadama and Kamburugamuwa of Matara district from June to November 2018. A line transect method was employed perpendicular to the shore and randomly placed quadrats were used to identify and quantify the species. Collectively 34 species of intertidal macroinvertebrate fauna were identified. Shanon-Weiner index, Menhinick’s index, and Pielou’s index for Wellamadama were 1.8271, 0.5612, and 0.7620 respectively, while those in Kamburugamuwa were 1.9281, 0.4307, and 0.7517. Higher species diversity was recorded at the rocky shores of Kamburugamuwa, while higher species richness and evenness at Wellamadama rocky shores. The Jaccard similarity index indicates a low similarity (<50%) between two study rocky shores. Clypidina notata, Cellana rota, and Patelloida striata were the dominant species in the low tide zone. Highly abundant species in mid tidal zone at Wellamadama was Nodilittorina quadricincta, while that of in mid-tide zone at Kamburugamuwa was Chiton sp. Periwinkle snails were dominating the high tide zone of both study rocky shores of which Nodilittorina trochoides dominated at Wellamadama and Littoraria undulata dominated at Kamburugamuwa. The study indicates that community assemblages in intertidal rocky shores vary spatially and comprehensive studies are essential to investigate the controlling factors.

Palmaria hecatensis sp. nov. (Rhodophyta, Palmariales) from British Columbia and Alaska with a survey of other Palmaria species

1985 ◽  
Vol 63 (3) ◽  
pp. 474-482 ◽  
Author(s):  
Michael W. Hawkes
Keyword(s):  
British Columbia ◽  
Pacific Ocean ◽  
Geographical Distribution ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Aleutian Islands ◽  
Rocky Shores ◽  
Intertidal Zones ◽  
The North ◽  
The North Pacific

Palmaria hecatensis sp. nov. is described based on material from northern British Columbia. Male gametophytes and tetrasporophytes are thick, coriaceous, flattened blades, linear to lobed in habit and arise from an extensive encrusting basal holdfast. Putative female gametophytes are microscopic multicellular discs. Palmaria hecatensis grows on rocky shores in the midintertidal to lower intertidal zones and has a known geographical distribution from Nootka Island, Vancouver Island, B.C., to Shemya Island in the Aleutian Islands, Alaska. Palmaria hecatensis is compared with other species in the genus and, in addition, another distinctive (and possibly undescribed) Palmaria species from British Columbia and Alaska is discussed, bringing the total number of Palmaria species reported in the North Pacific Ocean to six.

The influence of food availability, quality and body size on patch selection of coexisting grazer ungulates in western Serengeti National Park

2019 ◽  
Vol 46 (1) ◽  
pp. 54 ◽  
Author(s):  
John Bukombe ◽  
Andrew Kittle ◽  
Ramadhan B. Senzota ◽  
Hamza Kija ◽  
Simon Mduma ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Niche Overlap ◽  
Wildlife Habitat ◽  
Management Tool ◽  
Conservation Strategies ◽  
Patch Selection ◽  
Wet Season ◽  
Serengeti Ecosystem ◽  
Dietary Niche

Context Differences in body size and mouth morphologies influence dietary resource separation among savanna ungulates, and this influences their distribution across landscape. Aim The aim was to understand the influence of body size and mouth morphology differences on both diet and patch selection by ungulate species in western Serengeti. Two hypotheses were tested: (1) for ungulate species, the relative body sizes and muzzle widths (mean muzzle width range: 3.1- 9.85) relate directly to food biomass, and to quality of diets selected in the wet season when food is abundant; (2) in the wet season, if food is not limiting, similar-sized species should exhibit greater dietary niche overlap than ungulate species that differ greatly in body size and muzzle width; moreover, similar-sized species exhibit less dietary niche overlap than ungulate species that differ greatly in body size. Methods In the western Serengeti ecosystem, road transects and direct observation were used to obtain data on the distribution and diet of five ungulate species namely buffalo, zebra, wildebeest, topi and impala; which have of varying sizes (range: 70–630kg) feeding in three different vegetation types. Grassland biomass, structure, nutrient content and ungulate use were measured at sites along transects. Key Results Results indicated that large-bodied ungulates utilised patches of greater food abundance compared with those of smaller ungulates. Body mass was also negatively correlated with diet quality, so that smaller animals ate higher protein and lower-fibre foods, as predicted. Diet niche overlap (niche similarity) showed a strong positive relationship with body mass differences among ungulate species, in support of the second of the two predictions from this hypothesis, namely that dissimilarly sized species could eat the same food. Conclusion Overall, the results suggest that in this savanna system, variation in ungulate body size influences resource separation even in the food-abundant wet season, and that this helps multiple species to co-exist. Implications Implementing more focused conservation strategies will improve wildlife habitat quality by integrating fire as a forage management tool with grazing preferences to promote forage heterogeneity in protected areas.

scholarly journals Drift-Ice Abrasion Marks along Rocky Shores

1985 ◽  
Vol 31 (109) ◽  
pp. 237-241 ◽  
Author(s):  
Jean-Claude Dionne
Keyword(s):  
Hudson Bay ◽  
Rocky Shores ◽  
Tidal Zone ◽  
Cold Regions ◽  
Lawrence Estuary ◽  
Soft Rocks ◽  
Rock Fragments ◽  
Ice Floes ◽  
St Lawrence Estuary ◽  
Fluvial Environments

AbstractDrift-ice abrasion marks are common along present-day rocky shorelines in cold regions. They include polished surfaces, scratches, striations, small grooves, and minor friction cracks. Most are found on relatively soft rocks like shale, sandstone, limestone, dolomite, and basalt, and occasionally on harder rocks like granite and gneiss. They were made by rock fragments frozen at the base of ice cover or by ice floes pushed onshore by wind or dragged along the bottom by waves, tides, and currents. They are found both in the modern and Pleistocene marine, lacustrine, and fluvial environments. Along the Hudson Bay eastern shoreline, these abrasion marks are superimposed on glacially polished and striated surfaces. Along the St. Lawrence Estuary, they are more common on boulders in the tidal zone. Characteristics of drift-ice abrasion marks are described and their significance is pointed out.

Fire, growth and survivorship in a Neotropical savanna grass Andropogon semiberbis in Venezuela

1989 ◽  
Vol 5 (4) ◽  
pp. 387-400 ◽  
Author(s):  
Juan F. Silva ◽  
Fernando Castro
Keyword(s):  
Seedling Growth ◽  
Canopy Structure ◽  
Structural Complexity ◽  
Dry Season ◽  
Root Competition ◽  
Annual Rainfall ◽  
Grass Species ◽  
Mortality Factors ◽  
Wet Season ◽  
Adult Plants

ABSTRACTThis study was conducted in a woodland savanna in western Venezuela exclosed from grazing and burnt once a year towards the end of the dry season. Mean annual rainfall is 1500 mm, with a strong seasonality.Two cohorts of seedlings of Andropogon semiberbis were tagged and monitored for up to three years. Several variables such as survivorship, plant size, seedling density, fire damage and distance to the nearest adult were measured or estimated. Two burning experiments to measure survivorship before and after fire, and two seedling-growth experiments to assess competitive interference from adult plants of three grass species were performed.The highest mortality takes place during the dry season and is due to fire. This decreases as the plants get bigger due to increasing structural complexity of the clump by growth which gives added protection to the meristems. Other mortality factors such as desiccation, uprooting and shading seem to be important during the wet season, when mortality rate is relatively constant. Survivorship during the first year and after three years is strongly correlated to the size attained by the end of the first growing season.Seedling densities are rather low and do not seem to play any role in survivorship in this population. Adult interference with seedling growth decreases with distance and seems to be due to root competition, although there is a tendency toward increased foliage interference related to the canopy structure of adult plants.

scholarly journals Between the Rocks and the Waves: Legislation and perceptions of the Exploitation of Perna perna from the Rocky Shores of Santa Catarina Island

2020 ◽  
pp. 87-106
Author(s):  
Thaís Fonseca Rech ◽  
Marinez Garcia Scherer
Keyword(s):  
Human Consumption ◽  
Rocky Shores ◽  
Perna Perna ◽  
Santa Catarina ◽  
The North ◽  
Rotation Methods ◽  
Capture Method ◽  
Commercial Purpose ◽  
The Waves ◽  
Provisioning Services

The removal of shellfish (Perna perna) from de rocky shores for human consumption is a traditional activity in Santa Catarina Island (ISC), Florianopolis, Brazil, constituting a provisioning ecosystem service. This activity is originally linked to fishing and subsistence; however, it acquired commercial purpose after the 1980’s. After the 1990’s, shellfish started to be exploited as seeds for mariculture, increasing pressure on natural stocks. It is fundamental to know the aspects of the extraction of shellfish to manage this resource. This work sought to fill in the gaps in the knowledge on the extraction, the main points being the identity of the actors involved, the location of extraction sites and the legislation relating to the activity. As to describe the characteristics of this activity, a set of interviews took place with key members of the neighboring communities, experts in related fields, and with beach goers in eight locations in ISC. The legislation found covers several of the points required for the management of the activity; however, no indication of supervision by the competent bodies was found, nor the required licenses were issued. The stocks are located on the rocky stretches of the East side of the island and on the more exposed parts of the North shore. The purpose of the mussels affected the capture method: mussels intended for commercialization was extracted by diving while mussels for own consumption were extracted from subaerial shores. All the extractors located were male and lived in Florianopolis, who favor summer months and extract only occasionally. The extractors believe that the amount of available P. perna has decreased, but the change of the source of mariculture seeds from rocky shores to artificial collectors decreased the pressure on said shores, but their rotation methods used are rudimentary. Failures in management, in rotation, in the issuing licenses, lack of supervision, and pollution are the main threats in maintaining the provision of service represented by mussels. This research subsidizes the decision making and serves as bases for other studies on provisioning services of the natural rocky coasts. Keywords: Mussels, Coastal Management, Provisioning services.

scholarly journals Artificial shorelines lack natural structural complexity across scales

2021 ◽  
Vol 288 (1951) ◽  
pp. 20210329
Author(s):  
Peter J. Lawrence ◽  
Ally J. Evans ◽  
Tim Jackson-Bué ◽  
Paul R. Brooks ◽  
Tasman P. Crowe ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Laser Scanner ◽  
Structural Complexity ◽  
Economic Benefits ◽  
Coastal Development ◽  
Rocky Shores ◽  
Coastal Structures ◽  
Direct Role ◽  
Living Space ◽  
Sensing Platforms

From microbes to humans, habitat structural complexity plays a direct role in the provision of physical living space, and increased complexity supports higher biodiversity and ecosystem functioning across biomes. Coastal development and the construction of artificial shorelines are altering natural landscapes as humans seek socio-economic benefits and protection from coastal storms, flooding and erosion. In this study, we evaluate how much structural complexity is missing on artificial coastal structures compared to natural rocky shorelines, across a range of spatial scales from 1 mm to 10 s of m, using three remote sensing platforms (handheld camera, terrestrial laser scanner and uncrewed aerial vehicles). Natural shorelines were typically more structurally complex than artificial ones and offered greater variation between locations. However, our results varied depending on the type of artificial structure and the scale at which complexity was measured. Seawalls were deficient at all scales (approx. 20–40% less complex than natural shores), whereas rock armour was deficient at the smallest and largest scales (approx. 20–50%). Our findings reinforce concerns that hardening shorelines with artificial structures simplifies coastlines at organism-relevant scales. Furthermore, we offer much-needed insight into how structures might be modified to more closely capture the complexity of natural rocky shores that support biodiversity.

scholarly journals Fish species richness in shallow environments of the Island of Santa Catarina, Southern Brazil

2018 ◽  
Vol 7 ◽  
pp. e20018001
Author(s):  
André Pereira Cattani ◽  
Olímpio Rafael Cardoso ◽  
Gisela Costa Ribeiro ◽  
Marcelo Soeth ◽  
Maurício Hostim-Silva ◽  
...  
Keyword(s):  
Species Richness ◽  
Fish Assemblages ◽  
Abiotic Factors ◽  
Fish Fauna ◽  
Sandy Beaches ◽  
Mean Value ◽  
Taxonomic Structure ◽  
Rocky Shores ◽  
Santa Catarina ◽  
Mean Values

The Island of Santa Catarina is a mosaic of ecosystems of great importance for fish fauna, highlighting the presence, in the same island, of estuaries, lagoons, mangroves, rocky shores and sandy beaches. This study aimed to compare, based on species richness, fish assemblages between different ecosystems. Between 1981 and 2011, there were collected a total of 165 taxa of fish, distributed in 54 families, in six sampling sites, using casting net, sweep net, beach trawl and gill net. According to the species accumulation curve, that show the increase of the number of different species with the increase of the number of samples, for all sites, the curves of species recorded followed patterns similar to curves obtained by the Jacknife index. However, the number of species has stabilized only for samples collected in Saco dos Limões, Itacorubi Mangrove and Ratones Mangrove. Comparing the mean values of richness between sites, the highest mean value was found in Saco dos Limões, followed by Índio Beach, Conceição Lagoon, North Bay , Itacorubi and Ratones Mangroves. Using the list of species as reference, despite the differences in abundance and richness between sites, the taxonomic structure is similar between sampling sites, which supports the hypothesis that the assemblages are occurring in all sites and the differences are primarily related to the patterns of reproduction and recruitment of species and secondarily influenced by abiotic factors, especially the temperature and salinity.

scholarly journals Patterns of body shape diversity and evolution in intertidal and subtidal lineages of combtooth blennies (Blenniidae)

2021 ◽  
Author(s):  
Joshua P Egan ◽  
Thaddaeus J Buser ◽  
Michael D Burns ◽  
Andrew M Simons ◽  
Peter J Hundt
Keyword(s):  
Body Size ◽  
Body Shape ◽  
Environmental Filtering ◽  
Morphological Diversity ◽  
Microhabitat Use ◽  
Tidal Zone ◽  
Intertidal Zones ◽  
Size Diversity ◽  
Intertidal Habitats ◽  
Body Shapes

Abstract Marine intertidal zones can be hasher and more dynamic than bordering subtidal zones, with extreme and temporally variable turbulence, water velocity, salinity, temperature, and dissolved oxygen levels. Contrasting environmental conditions and ecological opportunities in subtidal versus intertidal habitats may generate differing patterns of morphological diversity. In this study we used phylogenetic comparative methods, measurements of body length, and two-dimensional landmarks to characterize body shape and size diversity in combtooth blennies (Ovalentaria: Blenniidae) and test for differences in morphological diversity between intertidal, subtidal, and supralittoral zones. We found that subtidal combtooth blennies have significantly higher body shape disparity and occupy a region of morphospace three times larger than intertidal lineages. The intertidal morphospace was almost entirely contained within the subtidal morphospace, showing that intertidal combtooth blennies did not evolve unique body shapes. We found no significant differences in body size disparity between tidal zones, no correlations between body shape and tidal zone or body size and tidal zone, and no body shape convergence associated with tidal zone. Our findings suggest that a subset of combtooth blenny body shapes are suitable for life in both subtidal and intertidal habitats. Many species in regions of morphospace unique to subtidal combtooth blennies exhibit distinct microhabitat use, which suggests subtidal environments promoted morphological diversification via evolutionary microhabitat transitions. In contrast, limited intertidal body shape diversity may be due to strong selective pressures that constrained body shape evolution and environmental filtering that prevented colonization of intertidal zones by certain subtidal body shapes.

scholarly journals Avaliação quali-quantitativa de algas marinhas macrófitas ocorrentes na Praia da Vigia, Garopaba/SC

2015 ◽  
Vol 4 (1) ◽  
pp. 5-15
Author(s):  
Diorge Jônatas Marmitt ◽  
Elisete Maria De Freitas ◽  
Fabiele Marczinski ◽  
Adriane Flesh ◽  
Édina Aparecida Reis Blasi
Keyword(s):  
Ulva Lactuca ◽  
Santa Catarina ◽  
Sargassum Cymosum

O estudo teve por objetivo, identificar espécies e conhecer a estrutura da comunidade de algas da Praia da Vigia, Garopaba, Santa Catarina, pertencentes aos filos Rhodophyta (algas vermelhas), Phaeophyta (algas pardas) e Chlorophyta (algas verdes). Foram distribuídas 100 unidades amostrais de 0,25 m² de modo aleatório em nove pontos ao longo da praia, considerando locais de submersão contínua e imersão temporária. Foram registradas 15 espécies. O filo Rhodophyta foi representado por sete espécies, seguido por Chlorophyta e Phaeophyta, com cinco e três espécies cada. Os índices de diversidade estimados pelo Shannon (H’) e equabilidade de Pielou (J) foram, respectivamente, 1,95 nats.ind.-1 e 0,72. Os resultados obtidos indicam que a espécie de maior valor de importância foi Ulva lactuca, seguida por Chaetomorpha antennina e Sargassum cymosum. Além dos baixos valores de diversidade, houve pouca diferença na estrutura da comunidade e a distribuição das espécies entre os locais de inundação constante e temporária foi pequena.  

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