scholarly journals The hypoxia that developed in a microtidal estuary following an extreme storm produced dramatic changes in the benthos

2016 ◽  
Vol 67 (3) ◽  
pp. 327 ◽  
Author(s):  
James R. Tweedley ◽  
Chris S. Hallett ◽  
Richard M. Warwick ◽  
K. Robert Clarke ◽  
Ian C. Potter

Runoff from an extreme storm on 22 March 2010 led, during the next 3 months, to the formation of a pronounced halocline and underlying hypoxia in the upper reaches of the microtidal Swan–Canning Estuary. Benthic macroinvertebrates were sampled between January 2010 and October 2011 at five sites along 10km of this region. By mid-April, the number of species, total density, Simpson’s evenness index and taxonomic distinctness had declined markedly, crustaceans had disappeared and the densities of annelids and molluscs had declined slightly. These faunal attributes (except Simpson’s index) and species composition did not recover until after the end of the hypoxia. The survival of annelids and loss of crustaceans in this period reflects different sensitivities of these taxa to severe environmental stress. The results emphasise that microtidal estuaries with long residence times are highly vulnerable to the effects of environmental perturbations, particularly during warmer periods of the year.

2021 ◽  
Vol 29 (4) ◽  
pp. 345-353
Author(s):  
N. I. Kopytina ◽  
E. A. Bocharova

Fungi are the most active biodeteriorators of natural and man-made materials. The article presents generalizations of the studies (2001–2019) of communities of microscopic fungi within biofilms on various substrates: shells of live Mytilus (Mytilus galloprovincialis, 670 specimens) and Ostreidae (Crassostrea gigas, 90 specimens), fragments of driftwood (over 7,000), stones (40), concrete of hydrotechnical constructions along the shoreline (80) and wood between concrete blocks in constructions on the shores (80). The studies were carried out in Odessa Oblast, the coastal zone of Sevastopol and open area of the Black Sea. There were identified 123 species of micromycetes, belonging to 65 genera, 33 families, 21 orders, 10 classes, 4 divisions, 2 kingdoms: Fungi and Chromista (fungi-like organisms). The Chromista kingdom was represented by 1 species – Ostracoblabe implexa, on shells of C. gigas. The number of species of micromycetes on various substrates varied 23 (wood between concrete blocks of hydrotechnical constructions) to 74 (shells of M. galloprovincialis at the depths of 3 and 6 m). On all the substrates, the following species were found; Alternaria alternata, Botryotrichum murorum. The communities were found to contain pathogenic fungi Aspergillus fumigatus (shells of mollusks, stones, concrete), A. terreus (concrete), Fusarium oxysporum, Pseudallescheria boydii (shells of mollusks). The best representation was seen for the Pleosporales order – from 12.9% (shells of M. galloprovincialis, 0.3 m depth) to 33.3% (shells of C. gigas) of the species composition. Toxin-producing species of Microascales in mycological communities accounted for 1.6% (driftwood) to 40.0% (concrete), and were also observed on shells of Bivalvia – 11.1–32.3%. Similarity of species composition of mycological communities according to Bray-Curtis coefficient varied 21.1% (driftwood and concrete, 10 shared species) to 72.7% (shells of M. galloprovincialis, the depths of 3 and 7 m and shells of C. gigas, 45 shared species). Using graphs of indices of mean taxonomic distinctness (AvTD, Δ+) and variation (Variation in Taxonomic Distinctness index, VarTD, Λ+), we determined deviations of taxonomic structure of the studied mycological communities from the level of mean expected values, calculated based on the list of species, taking into account their systematic positions. The lowest values of index Δ+ were determined for communities on shells of M. galloprovincialis, 0.3 m depth, driftwood, stones and concrete. These communities had uneven distribution of species according to higher taxonomic ranks and minimum number of the highest taxa: 4–6 classes, 1–2 divisions, Fungi kingdom. Disproportion in species composition with decrease in the number of the highest taxa occurred in extreme environmental conditions. Using index Λ+, we found that the most complex taxonomic structure of fungi communities has developed on concrete and shells of C. gigas. In mycological communities on those substrates, the number of species was low (25 and 46), but they belonged to 4–7 classes, 2–3 divisions, 1–2 kingdoms. To compare the structures of mycological communities that have developed in such substrates in biotopes sea, sea-land-air, land-air, we compiled a list of fungi based on the literature data, which, taking into account our data, comprised 445 species of 240 genera, 103 families, 51 orders, 15 classes, 5 divisions, 2 kingdoms. The analysis revealed that on substrates with similar chemical composition, in all the biotopes, the species of the same divisions dominated (genus and family may vary). Therefore, in the biotope land-air – Hypocreales, Pleosporales, Eurotiales (genera Acremonium, Fusarium, Alternaria, Aspergillus, Penicillium); sea – Pleosporales, Eurotiales, Microascales (Alternaria, Aspergillus, Penicillium, Corollospora); sea-land-air – Pleosporales, Microascales (Alternaria, Leptosphaeria, Aspergillus, Penicillium, Corollospora, Halosarpheia). Monitoring of species composition of myxomycetes is needed in farms that cultivate industrial objects, recreation sites, various buildings for prevention of mycotoxin intoxication and infestation by mycodermatoses and other diseases caused by opportunistic and pathogenic fungi.


Author(s):  
M.D. Wildsmith ◽  
I.C. Potter ◽  
F.J. Valesini ◽  
M.E. Platell

Benthic macroinvertebrates were sampled seasonally in the subtidal and upper and lower swash zones at two sites in each of six nearshore habitat types on the lower west coast of Australia. The habitat types, which differed mainly in the extent of their exposure to wave activity and whether sea grass and/or nearshore reefs were present, had been distinguished quantitatively using values for a suite of seven statistically-selected enduring environmental characteristics (Valesini et al., 2003). The core samples yielded 121 species representing eight phyla, among which the Polychaeta, Malacostraca and Bivalvia were the most speciose classes, contributing ∼38, 23 and 10%, respectively, to the total number of individuals. The total number of species and mean density of macroinvertebrates at the most protected habitat type (1), i.e. 70 and 209·2 individuals 0·1 m−2, respectively, were far greater than in any other habitat type. Habitat type influenced species composition to a greater extent than either zone or season. Furthermore, the extents of the differences among the species compositions of the six habitat types statistically matched the extents of the differences among the values for the suite of enduring environmental characteristics that distinguished each of those habitat types. Overall, the species composition at habitat type 1 was the most distinct, containing five abundant species of polychaetes that were adapted to deposit-feeding in calm waters with high levels of organic material and which were rare in all other habitat types. In contrast, the fauna at the most exposed habitat type was characterized by four crustacean species and a species of bivalve and polychaete, whose mobility and tough external surface facilitated their survival and feeding in turbulent waters. The zonal differences in faunal compositions among habitat types were greatest in the case of the subtidal zone. The faunal compositions differed among zones and seasons only at the most protected habitat type.


2020 ◽  
Vol 206 ◽  
pp. 02024
Author(s):  
Li Guanglou ◽  
Cao Hongmei ◽  
Ye wei

According to a survey of benthos in the Laoting sea area of Hebei Province on May 24th 2019, a total of 40 benthos species were obtained, of which mollusks have the largest number, followed by annelids and arthropods. The dominant species are Sternaspis sculata and Ringicula doliaris. The number of species obtained in this survey is much lower than the historical average. The diversity index is significantly lower than that in the April 2008 survey, and the evenness index and richness index have declined slightly, indicating that the benthic community structure in this sea area tends to be simplistic, stability tends to deteriorate.


The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 761-779 ◽  
Author(s):  
Richard T. Reynolds ◽  
E. Charles Meslow

AbstractThe abundance of resources and their use by Accipiter in two areas within Oregon from 1969 through 1974 are presented. In the coastal mountains of northwestern Oregon only Sharp-shinned Hawks (Accipiter striatus) and Cooper's Hawks (A. cooperii) nested. In the remainder of the state, A. striatus, A. cooperii, and Northern Goshawks (A. gentilis) were syntopic during the nesting season. The number of species and the total density of birds in eastern Oregon were about one-half those in northwestern Oregon. Mean prey size of A. striatus in northwestern Oregon (12.8 g) was significantly smaller than that of the same species in eastern Oregon (28.4 g). Accipiter striatus diets in both areas were composed almost entirely of birds (<5% mammals). Mean prey size of A. cooperii in both areas was nearly the same (134.7 g vs. 136.3 g) and was significantly larger than mean prey size of A. striatus. The frequency of occurrence and the size of prey taxa in A. cooperii diets, however, varied between areas: 74% birds (x̄ = 79.2 g) and 25% mammals (x̄ = 296.4 g) in northwestern Oregon versus 47% birds (x̄ = 123.7 g) and 53% mammals (x̄ = 147.5 g) in eastern Oregon. Mean prey size of A. gentilis in eastern Oregon (306.6 g) was significantly larger than that of A. cooperii and consisted of 55% birds (x̄ = 195.5 g) and 45% mammals (x̄ = 445.2 g). An analysis of prey sizes, prey taxa, and foraging heights indicated that, in general, food was partitioned in both areas primarily according to prey size. In eastern Oregon, however, where A. cooperii and A. gentilis overlapped broadly in prey size, these species tended to take different prey taxa. Both A. cooperii and A. gentilis foraged primarily in the lower zones (ground-shrub and shrub-canopy), whereas A. striatus foraged in the upper canopy.


2015 ◽  
Vol 63 (4) ◽  
pp. 455-468 ◽  
Author(s):  
Hongju Chen ◽  
Guangxing Liu

Abstract Study on zooplankton spatial distribution is essential for understanding food web dynamics in marine ecosystems and fishery management. Here we elucidated the composition and distribution of large mesozooplankton on the continental shelf of the Yellow Sea and East China Sea, and explored the zooplankton community structure in these water masses. Sixty vertical hauls (bottom or 200 m in deep water to surface) using a ring net (diameter 0.8 m, 505-μm mesh) were exploited in November 2007. The biogeographic patterns of zooplankton communities were investigated using multivariate analysis methods; copepod biodiversity was analyzed using univariate indices. Copepods and protozoans were dominate in the communities. Based on the species composition, we divided the study areas into six station groups. Significant differences in zooplankton assemblages were detected between the Yellow Sea and East China Sea. Species richness was higher in East China Sea groups than those in Yellow Sea, whereas taxonomic distinctness was higher in Yellow Sea than in East China Sea. There was a clear relationship between the species composition and water mass group.


2014 ◽  
Vol 9 (8) ◽  
pp. 777-795
Author(s):  
Andrzej Szczepkowski ◽  
Błażej Gierczyk ◽  
Anna Kujawa

AbstractIn 2010, 16 macrofungi species were found in greenhouses of the Botanical Garden in Warsaw-Powsin. These included 8 species of lepiotaceous fungi and a few species known from warmer areas. For 3 species identified, which are new to Poland (Agaricus subrufescens, Leucocoprinus heinemannii, Marasmius teplicensis), a description is given, with drawings of their microscopic features and photographs. Species composition of macrofungi is compared in 5 complexes of greenhouses (Bayreuth, Graz, Jena, Paskov, Warsaw) in 4 countries from Central Europe. The total number of species in these 5 studies is 206, including 27 (13.2%) lepiotaceous fungi. The smallest number of species identified was in Warsaw (16). More than twice this number was recorded in Jena (33) and Graz (34), while the richest fungal biotas were in Bayreuth (79) and Paskov (88). Of the 16 species found in Warsaw, 8 were also found in other greenhouses. In the group of 33 species recorded in at least two complexes of greenhouses, the most abundant were the lepiotaceous fungi (39.4%) and mycenaceous fungi (15.1%). Leucocoprinus cepistipes and L. straminellus were recorded most often, in 4 of the 5 studied greenhouse complexes. CCA analysis demonstrated that the highest impact on species diversity is the area of greenhouses.


Check List ◽  
2014 ◽  
Vol 10 (2) ◽  
pp. 335 ◽  
Author(s):  
Nurulhuda Zakaria ◽  
Juliana Senawi ◽  
Fakhrul Hatta Musa ◽  
Daicus Belabut ◽  
Chan Kin Onn ◽  
...  

A revised and updated checklist of the herpetofauna of the Krau Wildlife Reserve (KWR), Pahang is presented, which includes 61 species of amphibians and 65 species of reptiles. Five species of amphibians are listed under revised names i.e. Hylarana labialis, H. picturata, Ansonia latiffi, Microhyla mantheyi and Rhacophorus norhayatae; and two species are listed as new locality records for KWR: Hylarana cf. siberu and Theloderma licin. The amphibians and reptiles recorded in KWR are approximately 56% and 22% of the total number of species recorded from Peninsular Malaysia, respectively.


1982 ◽  
Vol 60 (12) ◽  
pp. 3196-3205 ◽  
Author(s):  
Joseph B. Rasmussen

The heated area of Lake Wabamun prior to macrophyte harvesting had higher submerged macrophyte production, greater amounts of plant detritus in the sediment, and a higher standing crop of benthic macroinvertebrates than the unheated area. Species composition of the benthic macroinvertebrate community was also much different in the heated area with the warmest areas supporting a community dominated by tubificid oligochaetes (Limnodrilus hoffmeisteri and Tubifex tubifex), and the moderately heated areas supporting a community dominated by large Chironomus species (Chironomus plumosus and Chironomus atroviridis). Benthos of the unheated parts of the lake consisted mainly of smaller chironomid species such as Chironomus maturus, C. (cf.) staegeri, Polypedilum nubeculosum, Cladotanytarsus spp., and Tanytarsus spp. The heated area was subjected to mechanical macrophyte harvesting which removed the majority of the submerged macrophytes. This reduced the amount of plant detritus within the sediment and also the standing crop of benthic macroinvertebrates in the heated area. Species composition of the oligochaete-dominated community was not affected by harvesting. Species composition of the Chironomus-dominated area was greatly affected by harvesting and became more similar to that of the unheated area; densities of the large Chironomus species were reduced to low levels, while the densities of smaller chironomid species increased.


Zootaxa ◽  
2009 ◽  
Vol 2319 (1) ◽  
pp. 1-138 ◽  
Author(s):  
HANS-GEORG MÜLLER ◽  
FRANZ KRAPP

A complete account on the shallow-water Pycnogonida known up to now from depths between 0-30 m in the Caribbean Sea of Colombia is presented. Almost all the information included herein is based upon the data obtained by the first author during a 14-month fieldwork programme carried out at the Instituto de Investigaciones Marinas de Punta de Betin (INVEMAR) in Santa Marta, Magdalena department.        5312 specimens of 50 species, including 7 species new to science in the genera Ammothella (2), Tanystylum (1), Callipallene (2), Anoplodactylus (1) and Endeis (1), were collected from 179 samples at 45 stations. The area covered by this research ranges in the west from Punta Brava, just near the airport of Santa Marta, eastward to Punta el Diamante at the eastern border of the Tayrona National Park, extending over about 70 km of coastline. Additionally, 6 other pycnogonid species reported previously from outside this area, which are also known from the Caribbean Sea of Colombia are briefly reviewed.        The species from the Santa Marta area are described in detail, with comments on their intraspecific affinities, habitat preference, phenology, vertical distribution and geographic distribution.        Quantitative samples were taken approximately monthly at three stations at Bahía Concha over one year to compare the species composition from substrata of different structure, namely stands of the brown algae Digenia simplex and Sargassum cymosum on a dead Porites reef, and a stand of Thalassia testudinum, which was interspersed with dead coral substratum and coralline algae.        Number of species at all of these stations was found to be similar and species composition of the two species of brown algae almost identical. Achelia sawayai was by far the most numerous species in samples of Digenia simplex, whereas Tanystylum acuminatum and T. isabellae were most numerous in Sargassum cymosum. Species composition in Thalassia was rather different from that of the algal vegetation. In Thalassia, Ammothella appendiculata and A. exornata were the commonest species which were not found in Digenia and Sargassum.        No evidence was found that reproduction of pycnogonids in this tropical area is limited to certain periods of the year. One might presume a shorter reproductive cycle only for Tanystylum acuminatum, because ovigerous males appeared at the end of the rainy season in December and remained until May, therefore for most of the duration of the dry season.        Generally, number of species and specimens collected at all three quantitative sampling stations was rather variable from month to month, implying a heterogenous distribution within the substratum, which surely depend on the distribution of their food.        Zoogeographic patterns are at present almost impossible to interpret, owing to the limited information available on the distribution of most species. However, it can be seen that the Santa Marta region has a very high number of shallow-water pycnogonid species, compared with the fauna of Panamá and Belize, where only 34 and 33 species have been recorded, respectively. However, the high number of species found in the Santa Marta area may be a result of the extensive collecting efforts made over a period of more than one year.


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