'%Healthy Reefs for Healthy People - A Guide to Indicators of Reef Health and Social Well-being in the Mesoamerican Reef Region%'%by Melanie McField and Patricia Kramer% of 38

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Use of this index requires some training on

The distribution of samples within each group is

identification of foraminiferal assemblages. However,

recorded on a spreadsheet, and the FORAM Index is

a key advantage is the reliance on functional groups,

calculated using simple equations that require only

which are recognizable worldwide, thus minimizing

limited computer capabilities (see Appendix 3).

the need for local taxonomic specialists.

Usefulness

Status

The tremendous taxonomic diversity and widespread

occurrence of foraminifers make them potential

FORAM Index values for most areas in the region are

bioindicators for different types of pollution. Their hard

not available at this time. However, as an example,

tests (shells) are readily preserved and can record

in 1999, FORAM Index values for Glover's Reef Atoll,

evidence of environmental stress over time.

Belize, ranged from 1.8 to 3.2 with an average of 2.215.

Foraminifers make ideal bioindicators because:

These values indicate that the nutrient concentrations

· They are widely dispersed in marine

are higher than would be expected in this offshore

environments;

atoll, and that the water conditions are marginal for

· They live on and in sediment, which can act as a

reef growth and are not conducive to recovery (see

sink for pollution;

red flag). Some unpublished nutrient measurements

· They are relatively small and abundant, permitting

and analysis of ocean color images of fluvial plumes

statistically significant sample sizes to be collected

on the Honduran shelf offer some support for this

quickly and relatively inexpensively, ideally as

interpretation16,17.

a component of comprehensive monitoring

programs; and

A study of the same location 25 years prior found a

· Their relatively short life span, as compared with

greater abundance of symbiont-bearing taxa and a

long-lived colonial corals, facilitates differentiation

lower presence of heterotrophic taxa, specifically

between long-term water quality decline and

stress-tolerant heterotrophs18. Comparisons of

episodic stress events.

the 1975 and 1999 datasets suggest a decrease

in FORAM Index values at Glover's Reef Atoll in the

Therefore, the FORAM Index provides a tool for

last 25 years, indicative of declining water quality

assessing whether water quality in the environment

(increased nutrient availability).

is adequate to support the symbiotic feeding strategy

(mixotrophy) found in corals and some foraminifers14.

Data Needs

The collected foraminiferal shells can also be

FORAM Index baseline values need to be established

subjected to morphometric and geochemical analyses

for coral reef systems throughout the MAR and

in areas of suspected heavy-metal pollution. FORAM

Caribbean. Earlier studies with adequate foraminiferal

Index datasets can be used with other monitoring

assemblage data and archived sediment samples can

data in detailed multi-dimensional assessments.

be utilized to help provide historical context.

Pamela Hallock