TY - JOUR

T1 - Precision and cost-effectiveness of bioindicators to estimate nutrient regimes on coral reefs

AU - Vaughan, Eleanor J.

AU - Wynn, Peter M.

AU - Wilson, Shaun K.

AU - Williams, Gareth J.

AU - Barker, Philip A.

AU - Graham, Nicholas A.J

PY - 2021/9

Y1 - 2021/9

N2 - Bioindicators are useful for determining nutrient regimes in marine environments, but their ability to evaluate corals reefs in different ecological states is poorly understood. The precision, availability and congruency of eight potential bioindicators (brown macroalgae, green macroalgae, turf algae, cyanobacteria, soft corals, zoanthids, sponges, and sediment) and their stable isotopic and elemental signatures (δ15N, δ13C, %N, %C, and C:N Ratio) were assessed across 21 reefs in the Inner Seychelles. The coefficient of variation (CoV) for δ15N showed that green and brown macroalgae were highly precise (2.47 ± 0.95, n = 11; 4.68 ± 1.33, n = 16, respectively), though were less common on coral-mortality reefs relative to macroalgal-dominated ones. Zoanthids were also highly precise for δ15N (2.98 ± 1.20), but were more readily available regardless of reef state (n = 18). Congruency was low among these indicators, suggesting that different physiological mechanisms for nutrient processing have a stronger influence on a bioindicator's effectiveness than reef state.

AB - Bioindicators are useful for determining nutrient regimes in marine environments, but their ability to evaluate corals reefs in different ecological states is poorly understood. The precision, availability and congruency of eight potential bioindicators (brown macroalgae, green macroalgae, turf algae, cyanobacteria, soft corals, zoanthids, sponges, and sediment) and their stable isotopic and elemental signatures (δ15N, δ13C, %N, %C, and C:N Ratio) were assessed across 21 reefs in the Inner Seychelles. The coefficient of variation (CoV) for δ15N showed that green and brown macroalgae were highly precise (2.47 ± 0.95, n = 11; 4.68 ± 1.33, n = 16, respectively), though were less common on coral-mortality reefs relative to macroalgal-dominated ones. Zoanthids were also highly precise for δ15N (2.98 ± 1.20), but were more readily available regardless of reef state (n = 18). Congruency was low among these indicators, suggesting that different physiological mechanisms for nutrient processing have a stronger influence on a bioindicator's effectiveness than reef state.

KW - Pollution

KW - Stable isotopes

KW - Macroalgae

KW - Environmental monitoring

KW - Regime shifts

U2 - 10.1016/j.marpolbul.2021.112606

DO - 10.1016/j.marpolbul.2021.112606

M3 - Article

VL - 170

JO - Marine Pollution Bulletin

JF - Marine Pollution Bulletin

SN - 0025-326X

M1 - 112606

ER -