Macroinvertebrates and water quality: a teaching guide

Streams support a diverse community of plants and animals on or in the stream bed. These organisms comprise the benthos. Among the benthos are worms, molluscs, crustaceans, and larval insects. Insect larvae are usually the most numerous animals of the benthos. Collectively the animals of the benthos are known as benthic macroinvertebrates because of where they live, and their large size (often 10-35 mm)

Regional variability in the trophic requirements of shelf sea fisheries in the Northeast Atlantic, 1973-2000

Hydrographic, plankton, benthos, fisheries landings, and fish diet data from shelf sea areas in the Northeast Atlantic have been combined into an analysis of the foodweb structure and secondary production requirements of regional fisheries. Fish landings from the Baltic and North Sea are shown to be taken from a lower trophic level and are shown to be overall more planktivorous than those from shelf edge regions. The secondary production required per unit of landed fish from the North Sea was approximately half that for landings from the southwest approaches to the UK, referred to as the Celtic Seas, where zooplankton production accounted for only a small fraction of the secondary production demands of the fisheries. In the North Sea, variability in zooplankton production seems to have exerted a bottom-up effect on fish production, which in turn has exerted a top-down effect on the benthos. Conversely, Celtic Seas benthos production has been a bottom-up driver of fish production, which seems to have been independent of variability in plankton production.Thus, climate and fishing pressures can be expected to influence these regional fisheries in very different ways. Overall, the results indicate very strong spatial patterns in the fish foodweb structure and function, which will be important considerations in the establishment of regional management plans for fisheries

Komposisi dan Keanekaragaman Benthos dalam Menilai Kualitas Air Sungai Lematang, di Desa Tanjung Muning, Kecamatan Gunung Megang Kabupaten Muara Enim

Pada penelitian ini subyek yang akan dianalisis adalah komunitas benthos Sungai Lematang di wilayah desa Tanjung Muning, Kecamatan Gunung Megang, Kabupaten Muara Enim. Sesuai dengan tujuan penelitian yang telah dilakukan, telah dianalisis indeks keanekaragaman benthos berdasarkan contoh sedimen atau substrat lumpur yang diambil dari Sungai Lematang pada bulan Juli 2011 yang lalu. Berdasarkan pengamatan secara mikroskopis dapat diidentifikasi sebanyak 11 spesies benthos yang terdiri dari 3 spesies Gastropoda, 3 spesies Odonata, 2 spesies Bivalvia dan masing-masing 1 spesies dari Diptera, Coleoptera dan Decapoda. Semua jenis benthos yang teridentifikasi termasuk kedalam 7 kategori taksonomi atau taksa (Gastropoda, Diptera, Bivalvia, Odonata, Coleoptera and Decapoda). Kelimpahan benthos pada substrat lumpur sungai adalah 12 individu/liter (kiri sungai), 4 individu/liter (tengah sungai) dan 19 individu/liter (kanan sungai). Sesuai dengan Indeks Sahanon dan berdasarkan hasil analisis yang telah dilakukan bahwa indeks keanekaragaman pada ketiga lokasi pengambilan contoh benthos adalah 1,04 (tengah sungai), 1,69 (kanan sungai) hingga 1,85 (kiri sungai). Rentang indeks keanekaragaman benthos pada tiga lokasi pengambilan contoh adalah 1,04 - 1,85 yang berarti bahwa kondisi komunitas benthos termasuk kedalam kriteria belum mantap (>1,00 - <2,00). Kondisi ini memperlihatkan bahwa jenjang pencemaran air sungai pada penelitian ini tergolong kedalam pada tingkat pencemaran ringat hingga sedang. Kesimpulan dalam penelitian ini sesuai dengan kriteria dari[8]. Kondisi pencemaran dalam penelitian ini kemungkinan berhubungan dengan bahanbahan pencemar anorganik maupun organik yang terdapat atau mengendap dalam substrat lumpur atau sedimen dimana komunitas benthos hidup

Final report : verification of bay productivity measurement by remote sensors

From University of Texas at Austin Marine Science Institute to Texas Water Development BoardInteragency cooperative contract TWDB contract no. IA03-483-003July 2004Ecosystem function in estuarine environments is known to be an important indicator of ecosystem health and productivity. There is a need to quantify estuarine ecosystem function variability and link to freshwater inflow to enable better management of ecosystem health and productivity. An important and quantifiable component of ecosystem function is ecosystem metabolism. Results indicate that open water methods were more appropriate than light-dark bottle methods for measuring net ecosystem metabolism in shallow water estuarine ecosystems because of the large contribution of benthos, which is ignored in water bottles. Spatial and temporal variability in net ecosystem metabolism was found. Spatial variability was attributed to differences in benthic habitats and/or station locations with respect to freshwater inflow point sources. Temporal variability in net ecosystem metabolism may be driven by differences in seasonal temperatures and freshwater inflow differences on seasonal time scales. Net ecosystem metabolism was directly related to amounts of freshwater inflow. The strength of this relationship depended on proximity to freshwater sources. Future studies of whole ecosystem metabolism in shallow estuarine ecosystems should employ open water methods and should strive to link other dynamic environmental conditions, such as temperature or irradiance, to ecosystem health, function, and productivity.Marine Scienc

A bibliography of samplers for benthic invertebrates

This annotated bibliography covers literature to the end of November 1977, and includes references to samplers that could be used for the rapid removal of benthic invertebrates from natural substrata of rivers and streams. Marine samplers which have been, or could be, used in freshwater. Coverage of Russian literature is incomplete, although a selection of recent and important references are included. The references are arranged under the following headings, Reviews; Nets and quadrat samplers; Scoops, shovels and dredges; Grabs; Corers; Suction and air-lift samplers; Electroshocking samplers; Efficiencies and comparisons; and Samplers from catalogues. There is an index to samplers (by the common name) and an author index

On drift and diel vertical migration of bottom invertebrates of the Amur. [Translation from: Zoologicheskie Zhurnal 42 1601-1612, 1963.]

Planktobenthos was sampled in 1957-58 in the river Amur. A determination of the kind of organisms drifting in the mass of water of the Amur was carried out. Of special interest for the authors was the activity of drifting of benthic larvae

The impact of Rapido trawling for scallops, Pecten jacobaeus (L.), on the benthos of the Gulf of Venice

Rapido trawls are used to catch sole around the coast of Italy and to catch scallops in the northern Adriatic Sea but little is known about the environmental impact of this gear. Benthic surveys of a commercial scallop ground using a towed underwater television (UWTV) sledge revealed an expansive area of level, sandy sediment at 25 m characterized by high population densities of scallops (2.82 m-2 Aequipecten opercularis but fewer Pecten jacobaeus) together with ophiuroids, sponges, and the bivalve Atrina fragilis. Rapido trawls were filmed in action for the first time, providing information on the selectivity and efficiency of the gear together with its impact on the substratum and on the benthos. The trawls worked efficiently on smooth sand with ca. 44% catch rate for Pecten jacobaeus, of which 90% were >7 cm in shell height. Most organisms in the path of the trawl passed under or through the net; on average by-catch species only formed 19% of total catch by weight. Of the 78 taxa caught, lethal mechanical damage varied from 50% in soft-bodied organisms such as tunicates. A marked plot surveyed using towed UWTV before, then 1 and 15 h after fishing by Rapido trawl showed clear tracks of disturbed sediment along the trawl path where infaunal burrow openings had been erased. Abundant, motile organisms such as Aequipecten showed no change in abundance along these tracks although scavengers such as Inachus aggregated to feed on damaged organisms. There were significant decreases in the abundance of slow-moving/sessile benthos such as Pecten, Holothuria, and Atrina. Juvenile pectinids were abundant on the shells of Atrina. The introduction of a scheme of areas closed to trawling would protect highly susceptible organisms such as Atrina and enhance the chances of scallop recruitment to adjacent areas of commercial exploitation

DAMPAK PENGALIHAN LAHAN MANGROVE TERHADAP KEANEKARAGAMAN BENTHOS DAN STRATEGI KONSERVASI DI KECAMATAN JAYA BARU KOTA BANDA ACEH

Fitria ulfa. Judul: Dampak Pengalihan Lahan Mangrove terhadap KeanekaragamanBenthos dan Strategi Konservasi di Kecamatan Jaya Baru Kota Banda Aceh.Pembimbing (1) Prof. Dr. M. Ali S., M.Si. Pembimbing (2) Dr. Abdullah, M. SiABSTRAKPenelitian ini bertujuan untuk mengetahui dampak pengalihan lahanmangrove terhadap keanekaragaman benthos dan strategi konservasi di KecamatanJaya Baru Kota Banda Aceh. Penelitian ini dilaksanakan pada Bulan September -November 2014 di kawasan mangrove Kecamatan Jaya Baru Kota Banda Aceh.Metode yang digunakan metode survey dengan observasi langsung untuk dampakpengalihan lahan mangrove terhadap keanekaragaman benthos dan strategikonservasi disekitar lahan manggrove Kecamatan Jaya Baru Kota Banda Aceh.Stasiun penelitian dibagi dalam 4 stasiun menggunakan metode purposive samplingatas dasar pertimbangan keberadaan mangrove. Keanekaragaman benthos dianalisisdengan rumus indeks keanekaragaman, sedangkan dampak pengalihan dianalisisdengan deskripsi. Hasil analisis diperoleh keanekaragaman benthos pada lahan yangtelah direklamasi 1,18 dan pada lahan yang belum direklamasi 1,77 artinyakeanekaragaman benthos sedang. Kesimpulannya adalah pengalihan lahan mangrovemanjadi tambak masyarakat, kawasan pariwisata dan pemukiman pendudukberdampak negative terhadap keanekaragaman benthos dan rendahnya kesadaranmasyarakat terhadap pentingnya konservasi mangrove menyebabkan strategikonservasi di Kecamatan Jaya Baru Kota Banda Aceh masih sangat kurang sehinggaperlu dilakukan pembinaan dan peningkatan kesadaran masyarakat serta perludilakukan pemulihan dengan merehabilitas ekosistem mangrove.Kata kunci : lahan mangrove, keanekaragaman benthos, strategi konservas

Global sensitivity analysis of an end-to-end marine ecosystem model of the North Sea : factors affecting the biomass of fish and benthos

Comprehensive analysis of parameter and driver sensitivity is key to establishing the credibility of models of complex systems. This is especially so for models of natural systems where experimental manipulation of the real-world to provide controlled validation data is not possible. Models of marine ecosystems fall into this category, but despite the interest in these models for evaluating the effects of climate change and fishing on nutrient fluxes and the abundances of flora and fauna, none have yet been subjected to global sensitivity analysis. Here we present results of both local ‘one-at-a-time’ (OAT), and variance based global sensitivity analyses (GSA) of the fish and fishery aspects of StrathE2E, an end-to-end (nutrients to birds and mammals) ecosystem model of the North Sea. The sensitivity of the model was examined with respect to internal biological parameters, and external drivers related to climate and human activity. The OAT Morris method was first used to screen for factors most influential on model outputs. The Sobol GSA method was then used to calculate quantitative sensitivity indices. The results indicated that the fish and shellfish components of the model (demersal and pelagic fish, filter/deposit and scavenge/carnivore feeding benthos) were influenced by different sets of factors. Harvesting rates were directly influential on demersal and pelagic fish biomasses. Suspension/deposit feeding benthos were directly sensitive to changes in temperature, while the temperature acted indirectly on pelagic fish through the connectivity between model components of the food web. Biomass conversion efficiency was the most important factor for scavenge/carnivorous feeding benthos. The results indicate the primacy of fishing as the most important process affecting total fish biomass, together with varying responses to environmental factors which may be relevant in the context of climate change. The non-linear responses and parameter interactions identified by the analysis also highlight the necessity to use global rather than local methods for the sensitivity analysis of ecosystem models

Time- and depth-wise trophic niche shifts in Antarctic benthos

Climate change is expected to affect resource-consumer interactions underlying stability in polar food webs. Polar benthic organisms have adapted to the marked seasonality characterising their habitats by concentrating foraging and reproductive activity in summer months, when inputs from sympagic and pelagic producers increase. While this enables the persistence of biodiverse food webs, the mechanisms underlying changes in resource use and nutrient transfer are poorly understood. Thus, our understanding of how temporal and spatial variations in the supply of resources may affect food web structure and functioning is limited. By means of C and N isotopic analyses of two key Antarctic benthic consumers (Adamussium colbecki, Bivalvia, and Sterechinus neumayeri, Echinoidea) and Bayesian mixing models, we describe changes in trophic niche and nutrient transfer across trophic levels associated with the long- and short-term diet and body size of specimens sampled in midsummer in both shallow and deep waters. Samplings occurred soon after the sea-ice broke up at Tethys Bay, an area characterised by extreme seasonality in sea-ice coverage and productivity in the Ross Sea. In the long term, the trophic niche was broader and variation between specimens was greater, with intermediate-size specimens generally consuming a higher number of resources than small and large specimens. The coupling of energy channels in the food web was consequently more direct than in the short term. Sediment and benthic algae were more frequently consumed in the long term, before the sea-ice broke up, while consumers specialised on sympagic algae and plankton in the short term. Regardless of the time scale, sympagic algae were more frequently consumed in shallow waters, while plankton was more frequently consumed in deep waters. Our results suggest a strong temporal relationship between resource availability and the trophic niche of benthic consumers in Antarctica. Potential climate-driven changes in the timing and quality of nutrient inputs may have profound implications for the structure of polar food webs and the persistence of their constituent species, which have adapted their trophic niches to a highly predictable schedule of resource inputs