Benthic primary production budget of a Caribbean reef lagoon (Puerto Morelos, Mexico)

PLoS One. 2013 Dec 18;8(12):e82923. doi: 10.1371/journal.pone.0082923. eCollection 2013.

Abstract

High photosynthetic benthic primary production (P) represents a key ecosystem service provided by tropical coral reef systems. However, benthic P budgets of specific ecosystem compartments such as macrophyte-dominated reef lagoons are still scarce. To address this, we quantified individual and lagoon-wide net (Pn) and gross (Pg) primary production by all dominant functional groups of benthic primary producers in a typical macrophyte-dominated Caribbean reef lagoon near Puerto Morelos (Mexico) via measurement of O₂ fluxes in incubation experiments. The photosynthetically active 3D lagoon surface area was quantified using conversion factors to allow extrapolation to lagoon-wide P budgets. Findings revealed that lagoon 2D benthic cover was primarily composed of sand-associated microphytobenthos (40%), seagrasses (29%) and macroalgae (27%), while seagrasses dominated the lagoon 3D surface area (84%). Individual Pg was highest for macroalgae and scleractinian corals (87 and 86 mmol O₂ m(-2) specimen area d(-1), respectively), however seagrasses contributed highest (59%) to the lagoon-wide Pg. Macroalgae exhibited highest individual Pn rates, but seagrasses generated the largest fraction (51%) of lagoon-wide Pn. Individual R was highest for scleractinian corals and macroalgae, whereas seagrasses again provided the major lagoon-wide share (68%). These findings characterise the investigated lagoon as a net autotrophic coral reef ecosystem compartment revealing similar P compared to other macrophyte-dominated coastal environments such as seagrass meadows and macroalgae beds. Further, high lagoon-wide P (Pg: 488 and Pn: 181 mmol O₂ m(-2) lagoon area d(-1)) and overall Pg:R (1.6) indicate substantial benthic excess production within the Puerto Morelos reef lagoon and suggest the export of newly synthesised organic matter to surrounding ecosystems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anthozoa
  • Coral Reefs*
  • Ecosystem
  • Mexico
  • Seaweed

Grants and funding

This work was funded by German Research Foundation (DFG) grant Wi 2677/2-1 and Wi 2677/6-1 to C.W., and Bleaching Work Group funding within the CRTR project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.