Productivity and Production: Biomass Ratios of Bivalve and Gastropod Populations in an Eastern Canadian Estuary

1974 ◽  
Vol 31 (2) ◽  
pp. 167-177 ◽  
Author(s):  
Michael V. Burke ◽  
K. H. Mann

In a narrow, shallow estuary on the east coast of Canada, the dominant intertidal invertebrates were bivalve and gastropod molluscs. On a sand flat Mya arenaria produced 11.6 g∙m−2∙yr−1 flesh dry weight with a production:biomass ratio of 2.54, whereas Macoma balthica produced 1.93 g∙m−2∙yr−1 with a P:B ratio of 1.53. On a Spartina marsh, Littorina saxatilis produced 3.25 g∙m−2∙yr−1 with a P:B ratio of 4.11. Approximate P:B ratios were applied to biomass figures for four other species to give the following estimates of productivity: Mytilus edulis on Zostera beds 19.7 g∙m−2∙yr−1 flesh dry weight; M. edulis on Spartina beds 3.5 g∙m−2∙yr−1; Nassarius obsoletus 1.15 g∙m−2∙yr−1; Melampus lineatus 1.1 g∙m−2∙yr−1; Lacuna vincta 0.06 g∙m−2∙yr−1. A total production of the molluscs in the estuary is estimated at 4.7% of the production of Spartina and Zostera (all measured in kcal). It is postulated that molluscs are the chief primary consumers in the inlet.

2009 ◽  
Vol 12 (3) ◽  
pp. 429-432 ◽  
Author(s):  
Anxo Conde ◽  
Júlio Novais ◽  
Jorge Domínguez

HortScience ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1618-1628
Author(s):  
Yanjun Guo ◽  
Terri Starman ◽  
Charles Hall

The objective was to determine the effect of substrate moisture content (SMC) during poinsettia (Euphorbia pulcherrima) greenhouse production on plant quality, postproduction longevity, and economic value. Two experiments were conducted, one in 2016 with ‘Freedom Red’ and the other in 2017 with ‘Christmas Eve Red’. Treatments included two SMC levels (20% or 40%) applied in four timing of application combinations. Total production (TP) time was 14 (2016) or 12 (2017) weeks in which vegetative production (VP) occurred from week 33 (2016) or 35 (2017) to week 39 and reproductive production (RP) continued from week 40 to 47. The four timing of application treatments were 40/40 = TP at 40% SMC; 20/40 = VP at 20% + RP at 40%; 40/20 = VP at 40% + RP at 20%; 20/20 = TP at 20% SMC. After simulated shipping in the dark, plants were evaluated in a simulated retail environment with two packaging treatments: no sleeve covering or plastic perforated plant sleeves covering container and plant. At the end of greenhouse production, plants grown in 20% SMC during RP (20/20 and 40/20) had shorter bract internode length, stem length, and smaller growth index (GI), decreased shoot and root dry weight (DW), and bract and leaf surface area compared with those in 40% SMC during RP (40/40 and 20/40). Photosynthetic rate was higher when plants were watered at 40% SMC regardless of production stage compared with those in 20% SMC. Leaf thickness, petiole thickness, total bract and leaf number were unaffected by SMC treatments. Plants in 20% SMC during RP (20/20 or 40/20) had earlier bract coloring despite days to anthesis being the same for all SMC treatments. Compared with 40/40, 40/20, and 20/20 could save 44.2% or 43.6%, respectively, irrigation and fertilizer usage, and 39.1% and 47.8%, respectively, labor time. During postharvest, ethylene concentration was unaffected by packaging method. Sleeved plants, regardless of SMC treatment, received lower light intensity in the middle of the plant canopy, causing plants to have lower total leaf number due to abscission and SPAD reading at the end of postproduction. The 40/40 treatment abscised more bracts during five weeks (in 2016) of postproduction and with no sleeve had higher number of bracts with bract edge burn (BEB). In summary, reducing SMC to 20% during TP or RP reduced water usage during production and produced more compact plants with increased postproduction quality.


2018 ◽  
Vol 10 (3) ◽  
pp. 639-650
Author(s):  
. Khairunnisa ◽  
Isdradjad Setyobudiandi ◽  
Mennofatria Boer

ABSTRAKSalah satu upaya untuk mengurangi emisi gas karbon pemicu pemanasan global adalah dengan memanfaatkan vegetasi pesisir seperti lamun yang dikenal dengan istilah blue carbon. Penelitian ini bertujuan untuk mengetahui stok karbon pada padang lamun di Pesisir Timur Kabupaten Bintan, Kepulauan Riau sebagai upaya dalam mengurangi pemanasan global. Penelitian dilakukan di Berakit, Malang Rapat, dan Teluk Bakau mulai Januari – Juli 2017. Parameter yang diukur dalam penelitian ini adalah biomassa, kandungan karbon, dan stok karbon pada lamun. Analisis biomassa diukur dari berat kering lamun per satuan luas yang dibagi atas bagian atas dan bawah substrat, kandungan karbon diukur dengan metode Walkley and Black, stok karbon diukur dengan memperhatikan kandungan karbon dan biomassa lamun. Hasil penelitian menunjukkan ekosistem lamun di pesisir timur Kabupaten Bintan ditumbuhi oleh C. rotundata, C. serrulata, E. acoroides, H. uninervis, H. pinifolia, H. ovalis, T. hemprichii, T. ciliatum dan S. isoetifolium dengan kondisi yang relatif baik.  Persentase biomassa dan karbon yang berada di bawah substrat lebih besar dibanding biomassa yang berada di atas substrat, sehingga ketika bagian pelepah dan daun lamun lepas baik karena tindakan manusia ataupun alam lamun masih tetap mampu menyimpan karbon. Padang lamun di pesisir sebelah timur Kabupaten Bintan memiliki potensi dalam menyerap dan menyimpan karbon yakni sebesar 2431.33 ton C dengan E. acoroides sebagai spesies yang mampu menghasilkan biomassa terbesar dan kandungan karbon tertinggi, meski jumlah tersebut tidak dapat dijadikan acuan apakah lamun memiliki potensi yang tinggi ataupun tidak karena hingga saat ini belum ada nilai standardnya. ABSTRACTOne of the solutions to reduce carbon gas emissions that triggered global warming is to utilize coastal vegetation such as seagrass that known as blue carbon. This research was aimed to determine stock carbon on seagrass in the east coast of Bintan Regency, Kepulauan Riau Province as an effort to reduce global warming.  The research was conducted in Berakit, Malang Rapat, and Teluk Bakau from January to July 2017. The parameters measured in this research were biomass, carbon content, and carbon stock on seagrass. The anylisis of the biomass was obtained from the dry weight per unit area, the carbon content was obtained by Walkley and black method, the carbon stock was obtained by the measurement of the biomass and carbon content. Based on the observation, seagrass ecosystem in east coast of Bintan was palnted by C. rotundata, C. serrulata, E. acoroides, H. uninervis, H. pinifolia, H. ovalis, T. hemprichii, T. ciliatum, dan S. isoetifolium. The below ground biomass and carbon percentation were higher that the aboveground parts so when the leaves are released either because of human or natural actions, seagrass is still able to store carbon. Seagrass beds on the east coast of Bintan Regency have the potential to absorb and store carbon which is equal to 2431.33 tons C as E. acoroides being the species which capable of producing the highest biomass and highest carbon content, although this number cannot be used as a reference whether seagrass has high potential or no because until now there has been no standard value. 


1994 ◽  
Vol 51 (4) ◽  
pp. 933-941 ◽  
Author(s):  
Emily Monosson ◽  
John J. Stegeman

Cytochrome P4501A (CYP1A), Aroclor 1254 (A1254), and 3,3′,4,4′-tetrachlorobiphenyl (TCB) were measured in liver of winter flounder, Pleuronectes americanus, from Boston Harbor, Mass., Hempsted Harbor, N.Y., Niantic, Conn., and an offshore site, Georges Bank. We also measured CYP1A content and activity in flounder from Passamaquoddy Bay, N.B. Concentrations of A1254 and TCB were the least in fish from Georges Bank (0.46 and 0.002 μg∙g dry weight−1, respectively); concentrations in fish from Boston, Niantic, and Hempsted ranged from 7.6 to 11.3 μg∙g−1 and from 0.013 to 0.024 μg∙g−1. Immunodetected microsomal CYP1A contents (expressed as scup P450E equivalents) were 0.17 and 0.19 nmol∙mg−1 in fish from Georges Bank and Passamaquoddy and 0.25–0.41 nmol∙mg−1 in fish from Boston, Niantic, and Hempsted. Ethoxyresorufin-O-deethylase specific activities likewise were greater in fish from Boston, Niantic, and Hempsted (1.7–2.4 nmol∙min−1∙mg−1) than in fish from Georges Bank or Passamaquoddy (0.83 and 0.61 nmol∙min−1∙mg−1). CYP1A content and activity were correlated with hepatic concentrations of A1254 and TCB. These data, together with data reported in previous studies, indicate that strong induction of CYP1A protein occurs in winter flounder populations along most of the industrialized east coast and that induction of CYP1A is common, but less strong, at sites distant from the urban centers of the Northeast.


Author(s):  
James H. Fraser

1. An ecological survey of the fauna of Dingle Beach, Mersey Estuary, has been made.2. A detailed analysis of the constituents of the mud, sand and gravel is given.3. A quantitative analysis of the Molluscan fauna from a series of stations has been made.4. Type of ground and fauna at different tidal levels are correlated.Mya arenaria is only found in abundance where there are stones. Macoma balthica is abundant wherever there is thick mud.5. Dingle Beach is a type of Macoma community but differing markedly from the typical community described by Petersen as “d”.6. The importance of sewage in producing silt and the part played by sewage in the food chain are discussed.


1974 ◽  
Vol 31 (3) ◽  
pp. 355-359 ◽  
Author(s):  
I. A. Moore ◽  
J. W. Moore

One hundred shorthorn sculpins, Myoxocephalus scorpius, over 15 cm in length captured from June to October, 1972, in Cumberland Sound, Baffin Island, fed almost exclusively (90% by both numbers and dry weight) on the planktonic amphipods Pseudalibrotus glacialis and Parathemisto libellula. In contrast, 140 fish captured about the same times from nearby Pangnirtung Fjord fed heavily on the benthic gastropods Littorina saxatilis and Margarites umbilicalis (each 34% by numbers and 22% by weight) and the bivalve Modiolaria discors (16% by both). Drifting ice on Cumberland Sound probably reduced the level of illumination making the detection of benthic prey difficult and causing the sculpins in this area to feed entirely on the better illuminated, brightly colored plankton. At both localities, the most abundant species in the plankton and the epifauna were also the most frequently encountered in gut contents. On the other hand, coelenterates, planktonic gastropods, copepods, and infauna, all of which were abundant in the environment, were rarely eaten.


2019 ◽  
Vol 73 (1) ◽  
Author(s):  
J. J. Beukema ◽  
R. Dekker

Abstract For a better understanding of functioning and stability of ecosystems, it is important to know to what extent constituent species show similarity in their long-term fluctuation patterns, i.e. whether their numbers and biomass frequently show simultaneous peaks and lows. Synchronic peaks and lows of important species would enhance variability in the functioning of the entire system and might affect its stability. When fluctuation patterns of individual species are largely independent, their peaks and lows would tend to extinguish each other’s effect on overall parameters (such as total zoobenthic biomass), thus promoting system stability. A long-term (46 years) monitoring study of the macrozoobenthos in a large (50 km2) tidal-flat area revealed that the 4 most important bivalve species (3 suspension feeders: Cerastoderma edule, Mytilus edulis, Mya arenaria and 1 deposit/suspension feeder: Limecola (Macoma) balthica) frequently showed peak numbers of their recruits in the same years. The annual growth rates of the three suspension feeding species showed some synchrony as well. Annual survival rates, on the other hand, did not show any synchronization, wiping out the initial synchrony of numbers within less than 2 years. As a result, annual biomass values did not show any positive between-species correlations. Annual amounts of bivalves that are accessible as bird food rarely declined to levels below 5 g AFDW m−2 and showed limited (5 to 10 fold difference between maximal and minimal values) variation. Oystercatchers left the area quicker in late winter and showed increased death rates at very low levels of food supply. Total bivalve bird food did not show any significant long-term trend. However, biomass of Mya arenaria showed an increasing trend and that of Limecola balthica a declining trend.


Author(s):  
S. W. B. Irwin ◽  
B. C. Irwin

Overall incidence of metacercariae of Maritrema arenaria differed substantially at each of the three sites investigated. In each case, however, numbers were higher than those previously observed in the British Isles. Results indicate that gulls rather than waders are the more important final hosts of this parasite in the areas investigated. At one site where a more detailed survey was carried out metacercariae were more abundant on the upper half of the shore and they displayed a marked preference for barnacles on living Littorina littorea shells as compared to barnacles on rocks. Evidence would suggest that the two most likely molluscan hosts of this trematode are Littorina saxatilis and Nucella lapillus.


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