Evidence map›Paper›PMID 37939036›Full record

ArticlePloS one2023

Isotopic signatures induced by upwelling reveal regional fish stocks in Lake Tanganyika.

Benedikt Ehrenfels, Julian Junker, Demmy Namutebi, Cameron M Callbeck, Christian Dinkel, Anthony Kalangali, Ismael A Kimirei, Athanasio S Mbonde, Julieth B Mosille, Emmanuel A Sweke and 4 more

Abstract read
In one paragraph

Article in PloS one, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

14 authors.

Benedikt EhrenfelsEawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Waters - Research and Management, Kastanienbaum, Switzerland.ORCID 0000-0002-7154-9282
Julian JunkerEawag, Swiss Federal Institute of Aquatic Science and Technology, Department Fish Ecology and Evolution, Kastanienbaum, Switzerland.
Demmy NamutebiInstitute of Ecology & Evolution, University of Bern, Bern, Switzerland.
Cameron M CallbeckEawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Waters - Research and Management, Kastanienbaum, Switzerland.ORCID 0000-0001-7602-3338
Christian DinkelEawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Waters - Research and Management, Kastanienbaum, Switzerland.
Anthony KalangaliTAFIRI, Tanzania Fisheries Research Institute, Kigoma, Tanzania.
Ismael A KimireiTAFIRI, Tanzania Fisheries Research Institute, Kigoma, Tanzania.ORCID 0000-0002-1101-5262
Athanasio S MbondeTAFIRI, Tanzania Fisheries Research Institute, Kigoma, Tanzania.
Julieth B MosilleTAFIRI, Tanzania Fisheries Research Institute, Kigoma, Tanzania.
Emmanuel A SwekeTAFIRI, Tanzania Fisheries Research Institute, Kigoma, Tanzania.
Carsten J SchubertEawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Waters - Research and Management, Kastanienbaum, Switzerland.ORCID 0000-0003-1668-5967
Ole SeehausenEawag, Swiss Federal Institute of Aquatic Science and Technology, Department Fish Ecology and Evolution, Kastanienbaum, Switzerland.ORCID 0000-0001-6598-1434
Catherine E WagnerDepartment of Botany and Program in Ecology, University of Wyoming, Laramie, Wyoming, United States of America.ORCID 0000-0001-8585-6120
Bernhard WehrliEawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Waters - Research and Management, Kastanienbaum, Switzerland.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Lake Tanganyika's pelagic fish sustain the second largest inland fishery in Africa and are under pressure from heavy fishing and global warming related increases in stratification. The strength of water column stratification varies regionally, with a more stratified north and an upwelling-driven, biologically more productive south. Only little is known about whether such regional hydrodynamic regimes induce ecological or genetic differences among populations of highly mobile, pelagic fish inhabiting these different areas. Here, we examine whether the regional contrasts leave distinct isotopic imprints in the pelagic fish of Lake Tanganyika, which may reveal differences in diet or lipid content. We conducted two lake-wide campaigns during different seasons and collected physical, nutrient, chlorophyll, phytoplankton and zooplankton data. Additionally, we analyzed the pelagic fish-the clupeids Stolothrissa tanganicae, Limnothrissa miodon and four Lates species-for their isotopic and elemental carbon (C) and nitrogen (N) compositions. The δ13C values were significantly higher in the productive south after the upwelling/mixing period across all trophic levels, implying that the fish have regional foraging grounds, and thus record these latitudinal isotope gradients. By combining our isotope data with previous genetic results showing little geographic structure, we demonstrate that the fish reside in a region for a season or longer. Between specimens from the north and south we found no strong evidence for varying trophic levels or lipid contents, based on their bulk δ15N and C:N ratios. We suggest that the development of regional trophic or physiological differences may be inhibited by the lake-wide gene flow on the long term. Overall, our findings show that the pelagic fish species, despite not showing evidence for genetic structure at the basin scale, form regional stocks at the seasonal timescales. This implies that sustainable management strategies may consider adopting regional fishing quotas.

Indexed as

CarbonLakesAnimalsFishesFood ChainIsotopesLipidsTanzaniaCarbonIsotopesLipids

Identifiers

PMID37939036
PMCPMC10631627

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.