Advertisement

Marine Biology

, Volume 148, Issue 2, pp 363–371 | Cite as

Food webs supporting fish over subtropical mudflats are based on transported organic matter not in situ microalgae

  • Andrew J. Melville
  • Rod M. Connolly
Resesarch Article

Abstract

We tested the importance of in situ microphytobenthos (MPB) and transported material (seagrass, seagrass epiphytic algae, mangroves, saltmarsh succulents and saltmarsh grass in adjacent habitats) as ultimate sources of carbon to fish caught over mudflats. We measured δ13C values of these 6 autotrophs and 22 fish species in the subtropical waters of Moreton Bay, Queensland, Australia. All fish δ13C values lay in the enriched half of the range for autotrophs. We modelled the distribution of feasible contributions of each autotroph to fishes, and then pooled the contributions for autotrophs with similar isotope values. Carbon from the suite of autotrophs having enriched isotope values (seagrass, epiphytes, saltmarsh grass) provided much of the carbon to fishes: 90–100% of carbon for 3 species, 70–90% for 13 species, and 50–70% for 5 species. For the one other species, the contribution of these autotrophs was lower (30–50%), and for this species the contribution of in situ MPB might be as much as about 50%. We could not, however, separate the MPB contribution from that of mangroves and saltmarsh succulents, which was also low for most species. Organic matter from seagrass meadows is clearly important at the base of food webs for fish on adjacent unvegetated mudflats. We are uncertain whether the apparent contribution of saltmarsh grass is real or a spurious result due to the similarity in isotope values of this autotroph and seagrass. This suite of fish caught over mudflats is supported by food webs relying predominantly on carbon from adjacent habitats and not in situ MPB.

Keywords

Macrophyte Suspended Particulate Matter Mangrove Forest Seagrass Meadow Adjacent Habitat 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

We thank K. Preston for processing microalgae samples, B. Thomas and G. Mount for help in the field and T. Gaston and M. Guest for comments on the manuscript. This project was funded by a Fisheries Research and Development Corporation grant to RMC. The survey in this study complies with current Australian law.

References

  1. Bouillon S, Koedam N, Raman AV, Dehairs F (2002) Primary producers sustaining macro-invertebrate communities in intertidal mangrove forests. Oecologia 130:441–448CrossRefGoogle Scholar
  2. Connolly RM (1995) Diet of juvenile King George whiting Sillaginodes punctata (Pisces: Sillaginodes) in the Barker Inlet—Port River estuary, South Australia. Trans Roy Soc South Aust 119:191–198Google Scholar
  3. Connolly RM (2003) Differences in trophodynamics of commercially important fish between artificial waterways and natural coastal wetlands. Est Coast Shelf Sci 58:929–936CrossRefGoogle Scholar
  4. Connolly RM, Guest MA, Melville AJ, Oakes JM (2004) Sulfur stable isotopes separate producers in marine food-web analysis. Oecologia 138:161–167CrossRefGoogle Scholar
  5. Connolly RM, Hindell JS, Gorman D (2005) Seagrass and epiphytic algae support the nutrition of a fisheries species, Sillago schomburgkii, in adjacent intertidal habitats. Mar Ecol Prog Ser 286:69–79CrossRefGoogle Scholar
  6. Currin CA, Newell SY, Paerl HW (1995) The role of standing dead Spartina alterniflora and benthic microalgae in salt marsh food webs—considerations based on multiple stable isotope analysis. Mar Ecol Prog Ser 121:99–116CrossRefGoogle Scholar
  7. Dennison WC, Abal EG (1999) Moreton Bay study: A scientific basis for the healthy waterways campaign. South East Queensland Regional Water Quality Management Strategy, BrisbaneGoogle Scholar
  8. Duarte CM, Cebrian J (1996) The fate of marine autotroph production. Limnol Oceanogr 41:1758–1766CrossRefGoogle Scholar
  9. Edgar G, Shaw C (1995) The production and trophic ecology of shallow-water fish assemblages in southern Australia II. Diets of fishes and trophic relationships between fishes and benthos at Western Port, Victoria. J Exp Mar Biol Ecol 194:83–106CrossRefGoogle Scholar
  10. Fry B, Macko SA, Zieman JC (1986) Review of stable isotopic investigations of food webs in seagrass meadows. Flor Mar Res Pub 42:189–209Google Scholar
  11. Gray CA, Chick RC, McElligott DJ (1998) Diel changes in assemblages of fishes associated with shallow seagrass and bare sand. Est Coast Shelf Sci 46:849–859CrossRefGoogle Scholar
  12. Guest MA, Connolly RM, Loneragan NR (2004a) Within and among-site variability in δ13C and δ15N for three estuarine producers, Sporobolus virginicus, Zostera capricorni, and epiphytes of Z. capricorni. Aquat Bot 79:87–94CrossRefGoogle Scholar
  13. Guest MA, Connolly RM, Loneragan NR (2004b) Carbon movement and assimilation by invertebrates in estuarine habitats occurring at a scale of metres. Mar Ecol Prog Ser 278:27–34CrossRefGoogle Scholar
  14. Hamilton SK, Sippel SJ, Bunn SE (2005) Separation of algae from detritus for stable isotope or ecological stoichiometry studies using density fractionation in colloidal silica. Limnol Oceanogr Methods 3:149–157CrossRefGoogle Scholar
  15. Kneib RT (2000) Saltmarsh ecoscapes and production transfers by estuarine nekton in the southeastern U. S. In: Weinstein MP, Kreeger DA (eds) Concepts and controversies in tidal marsh ecology. Kluwer, The Netherlands, pp 267–292Google Scholar
  16. Lee SY (1995) Mangrove outwelling—a review. Hydrobiologia 295:203–212CrossRefGoogle Scholar
  17. McCutchan J, Lewis W, Kendall C, McGrath C (2003) Variation in trophic shift for stable isotope ratios in carbon, nitrogen, and sulfur. Oikos 102:378–390CrossRefGoogle Scholar
  18. Melville AJ, Connolly RM (2003) Spatial analysis of stable isotope data to determine primary sources of nutrition for fish. Oecologia 136:499–507CrossRefGoogle Scholar
  19. Middelburg JJ, Barranguet C, Boschker HTS, Herman PMJ, Moens T, Heip CHR (2000) The fate of intertidal microphytobenthos carbon: an in situ 13 C-labeling study. Limnol Oceanogr 45:1224–1234CrossRefGoogle Scholar
  20. Moncreiff CA, Sullivan MJ (2001) Trophic importance of epiphytic algae in subtropical seagrass beds: evidence from multiple stable isotope analyses. Mar Ecol Prog Ser 215:93–106CrossRefGoogle Scholar
  21. Newsome SD, Phillips DL, Culleton BJ, Guilderson TP, Koch PL (2004) Dietary reconstruction of an early to middle Holocene human population from the central Californian coast: insights from advanced stable isotope mixing models. J Archaeol Sci 31:1101–1115CrossRefGoogle Scholar
  22. Odum EP (1984) The status of three ecosystem-level hypotheses regarding salt marsh estuaries: tidal subsidy, outwelling and detritus-based food chains. In: Kennedy VS (eds) Estuarine Perspectives. Academic Press, New York, pp 485–495Google Scholar
  23. Peterson BJ, Fry B (1987) Stable isotopes in ecosystem studies. Ann Rev Ecol Syst 18:293–320CrossRefGoogle Scholar
  24. Phillips DL, Gregg JW (2003) Source partitioning using stable isotopes: coping with too many sources. Oecologia 136:261–269CrossRefGoogle Scholar
  25. Robertson AI, Lenanton RJC (1984) Fish community structure and food chain dynamics in the surf-zone of sandy beaches: the role of detached macrophyte detritus. J Exp Mar Biol Ecol 84:265–283CrossRefGoogle Scholar
  26. Sinclair Knight Mertz (2000) Logan-Nerang estuarine habitats, Phase I report to Southeast Queensland Regional Water Quality Management Strategy, BrisbaneGoogle Scholar
  27. Thresher RE, Nichols PD, Gunn JS, Bruce BD, Furlani DM (1992) Seagrass detritus as the basis of a coastal planktonic food chain. Limnol Oceanogr 37:1754–1758CrossRefGoogle Scholar
  28. Tibbetts IR, Connolly RM (1998) The nekton of Moreton Bay. In: Tibbetts IR, Hall NJ, Dennison WC (eds) Moreton Bay and catchment. School of Marine Science, University of Queensland, Brisbane, pp 395–420Google Scholar
  29. Vander Zanden MJ, Rasmussen JB (2001) Variation in δ15N and δ13C trophic fractionation: implications for aquatic food web studies. Limnol Oceanogr 46:2061–2066CrossRefGoogle Scholar
  30. Wainright SC, Weinstein MP, Able KW, Currin CA (2000) Relative importance of benthic microalgae, phytoplankton and the detritus of smooth cordgrass Spartina alterniflora and the common reed Phragmites australis to brackish-marsh food webs. Mar Ecol Prog Ser 200:77–91CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Centre for Aquatic Processes & Pollution, and School of Environmental & Applied SciencesGriffith UniversityGold Coast Mail CentreAustralia

Personalised recommendations