Efficiencies of benthic and pelagic trophic pathways in a subalpine lake

2006 ◽  
Vol 63 (12) ◽  
pp. 2608-2620 ◽  
Author(s):  
M Jake Vander Zanden ◽  
Sudeep Chandra ◽  
Sang-Kyu Park ◽  
Yvonne Vadeboncoeur ◽  
Charles R Goldman

Although the study of lakes has traditionally focused on pelagic production pathways, recent stable isotope and diet evidence indicates that benthic algal production is an important contributor to fish production. This has led to the suggestion that energy may be more efficiently passed along benthic food chains relative to their pelagic counterparts. To test this idea, we combined stable isotope based assessments of energy flow pathways with estimates of pelagic- and benthic-based primary and secondary production in Castle Lake, California. Approximately 50% of whole-lake primary production and 30% of whole-lake secondary production occurred in benthic habitats. Stable carbon isotopes and dietary data indicated that fish were predominantly supported by benthic (63%) and terrestrial (24%) secondary production. Ecological efficiencies (algal production / invertebrate production) were low in Castle Lake (<3%), though zoobenthic production was more efficiently passed to fish than was zooplankton production. The larger size of benthic prey relative to pelagic prey may affect fish prey selection and foraging efficiency, resulting in differences in ecological efficiency between pelagic and benthic trophic pathways.

Author(s):  
Sosuke Otani ◽  
Sosuke Otani ◽  
Akira Umehara ◽  
Akira Umehara ◽  
Haruka Miyagawa ◽  
...  

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.


Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 195
Author(s):  
Qiang Qin ◽  
Fubin Zhang ◽  
Fei Liu ◽  
Chunling Wang ◽  
Huanzhang Liu

Understanding energy flow and nutrient pathways is crucial to reveal the dynamics and functions of riverine ecosystems and develop appropriate conservation strategies. In this study, we utilized stable isotopes of δ13C and δ15N to examine the fundamental characteristics of trophic position, trophic niche, and carbon source for the food web in the midstream of the Chishui River, a tributary to the Yangtze River. Our results showed that stable isotope signatures among different sorts of basal resources and consumers were significantly distinguishable and that the food chain consisted of four trophic levels, indicating the multiple trophic pathways and long food chain length here. The trophic guilds of fish were classified into four categories, in which herbivorous and carnivorous fish showed greater trophic diversity and omnivorous fish had higher trophic redundancy, which meant that there was a stable trophic niche structure in the study area. Phytoplankton and periphyton presented the largest contributions to consumers, indicating that autochthonous productivity was the dominant carbon source in the midstream of the Chishui River. Since the Chishui River is still in a natural condition without any dam constructions, the autochthonous productivity, stable trophic niche structure, multiple trophic pathways and long food chain length found here demonstrate its high conservation value. Therefore, the strategy to refrain from damming on this river should persist into the future.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246491
Author(s):  
Alex Souza Lira ◽  
Flávia Lucena-Frédou ◽  
Frédéric Ménard ◽  
Thierry Frédou ◽  
Júlio Guazzelli Gonzalez ◽  
...  

We used complementary stable isotope (SIA) and stomach content (SCA) analyses to investigate feeding relationships among species of the nektobenthic communities and the potential ecological effects of the bottom trawling of a coastal ecosystem in northeastern Brazil. Carbon (δ13C) and nitrogen (δ15N) compositions were determined for five basal sources and 28 consumers, from zooplankton to shrimp and fish species. Fishes and basal sources showed a broad range of δ15N (fishes: 6.49–14.94‰; sources: 2.58–6.79‰) and δ13C values (fishes: -23.86 to -13.71‰; sources: -24.32 to -13.53‰), while shrimps and crabs exhibited similar nitrogen and carbon ratios. Six trophic consumer groups were determined among zooplankton, crustaceans and fishes by SIA, with trophic pathways associated mostly with benthic sources. SCA results indicated a preference for benthic invertebrates, mainly worms, crabs and shrimps, as prey for the fish fauna, highlighting their importance in the food web. In overall, differences between SCA and the SIA approaches were observed, except for groups composed mainly for shrimps and some species of high δ15N values, mostly piscivorous and zoobenthivores. Given the absence of regulation for bottom trawling activities in the area, the cumulative effects of trawling on population parameters, species composition, potentially decreasing the abundance of benthic preys (e.g., shrimps, worms and crabs) may lead to changes in the trophic structure potentially affect the food web and the sustainability of the fishery.


<em>Abstract.</em>—Prey selection and diet are highly plastic and can vary with temporal and spatial differences in competition or prey availability. This study investigated the possibility that the trophic position of Smallmouth Bass <em> Micropterus dolomieu </em>might change in response to systematic, hierarchical variation in community structure in stream networks. We hypothesized that a shift toward increased insectivory and decreased piscivory would be observed in smaller streams, resulting in a lower trophic position of Smallmouth Bass and reflecting differences in community structure and prey availability. We applied a combination of diet analyses and stable isotope methods to compare prey selection and trophic position of Smallmouth Bass across a range of stream sizes. Stable isotope analyses indicated that Smallmouth Bass trophic position was slightly elevated in smaller watersheds, contradicting our initial hypothesis. However, differences in average trophic position in watershed size categories were small (ranging from 3.6 to 3.8) and of limited ecological significance. Isotopic niche width did not vary among stream size categories, and gut content analyses revealed no differences in frequency of occurrence of fish, crayfish, or insects (larvae and adults). Collectively these results indicate that trophic position, and perhaps trophic niche, of Smallmouth Bass are consistent across hierarchical variation in stream size and habitat.


1998 ◽  
Vol 49 (5) ◽  
pp. 421 ◽  
Author(s):  
P. M. Sagar ◽  
G. J. Glova

Benthic macroinvertebrates and three size classes of shortfinned eel (Anguilla australis, Anguillidae) were sampled in a lowland New Zealand stream over a 24-h period in summer to investigate diel feeding periodicity and prey selection. Fish of all three size classes fed mostly from post-dusk to dawn, with larger fish tending to consume a greater proportion of their prey during night-time. The number of prey taxa consumed increased with increasing size of fish. Prey selection indices indicated that: (1) the smallest eels (80–100 mm total length, TL) preferentially consumed ostracods (Crustacea) and larvae of Chironomidae (Diptera) and Psilochorema sp. (free-living Trichoptera); (2) medium-sized eels (101–199 mm TL) preferred larvae of Chironomidae, and Costachorema sp., Hydrobiosis sp. and Psilochorema sp.; and (3) large eels (200–300 mm TL) preferred ostracods, Psilochorema sp. and Hudsonema amabilis (cased Trichoptera). Eels of all size classes showed selection for soft-bodied or easily broken prey over those with hard cases which would have been more difficult to digest. There was considerable overlap in the diets of medium and large eels. Differences in the timing of feeding between the three size classes of eel are explained in terms of microhabitat use; differences in diet are explained in terms of prey size, and are also related to eel size.


2004 ◽  
Vol 116 (4) ◽  
pp. 2503-2504
Author(s):  
Whitlow W. L. Au ◽  
Kelly J. Benoit‐Bird ◽  
Ronald Kastelein ◽  
Sander van de Heul
Keyword(s):  

2012 ◽  
Vol 47 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Antonio Vilches ◽  
Rafael Miranda ◽  
Juan Arizaga
Keyword(s):  

1997 ◽  
Vol 75 (9) ◽  
pp. 1508-1518 ◽  
Author(s):  
Dominic J. Tollit ◽  
Paul M. Thompson ◽  
Simon P. R. Greenstreet

This study compared the composition of the diet of harbour seals (Phoca vitulina) feeding in the Moray Firth, Scotland, with the abundance of their fish prey estimated from dedicated fishery surveys in January 1992 and 1994 and June 1992. Prey-size selection was also examined in these three time periods and in January 1991. In each period, the most abundant fish species contributed most to the diet. However, the relative abundances of the remaining species in the sea showed little similarity to their contribution to the seals' diet. Diet composition was almost totally dominated by either pelagic species or species dwelling on or strongly associated with the seabed, depending upon the relative abundance of pelagic schooling prey. Most fish consumed were 10–16 cm in length, although larger cod and herring were taken. With the exception of cod, the extent of size selection was dependent upon the use of correction factors that accounted for otolith erosion due to digestion.


Author(s):  
Sosuke Otani ◽  
Sosuke Otani ◽  
Akira Umehara ◽  
Akira Umehara ◽  
Haruka Miyagawa ◽  
...  

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.


2008 ◽  
Vol 65 (12) ◽  
pp. 2719-2727 ◽  
Author(s):  
Marie-Elodie Perga ◽  
Martin Kainz ◽  
Asit Mazumder

Carbon stable isotope analyses have been widely used to estimate terrestrial carbon contribution to lake secondary production. In such approaches, phytoplankton is tacitly assumed as a single, isotopically homogenous source. Such assumption might be valid if (i) zooplankton do not feed selectively on specific algal taxa within bulk phytoplankton, or (ii) although zooplankton do feed selectively, the variability in the δ13C values amongst the different algal taxa is small compared with the variability between the δ13C values of bulk phytoplankton and terrestrial end-members. In a summer field study of six coastal lakes of British Columbia, Canada, we tested these assumptions using gut pigments and stable isotope measures on zooplankton and particulate organic matter. Results revealed that filter-feeding cladocerans positively selected cryptophytes, shown to be substantially 13C-enriched compared with bulk phytoplankton and even with the terrestrial end-member. Comparing a classical two-source mixing model and a model that accounted for algal isotopic heterogeneity, we showed that the use of a classical two-source model can result in an overestimation of terrestrial contribution to zooplankton secondary production.


Sign in / Sign up

Export Citation Format

Share Document