Seagrass species communities around Trinidad and Tobago

Data Records

The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 143 records.

1 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Institute of Marine Affairs, Juman R (2023). Seagrass species communities around Trinidad and Tobago. Version 1.2. Institute of Marine Affairs. Occurrence dataset. https://cloud.gbif.org/lac/resource?r=seagrass&v=1.2

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is Institute of Marine Affairs. This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: 1fcd74a8-d206-4edc-8471-cd84fda3bfdb.  Institute of Marine Affairs publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Participant Node Managers Committee.

Keywords

Occurrence; Seagrass; Trinidad and Tobago; Observation; Seagrass; Trinidad and Tobago

Contacts

Geographic Coverage

Coastal areas around Trinidad and Tobago

Taxonomic Coverage

The biodiversity found in these events consist of Plante: Seagrass, Algae and Mangrove and Animalia: Arthropoda, Chordata, Echinodermata and Mollusca The phylum of Arthropoda, Chlorophyta, Chordata, Chorophyta, Cnidaria, Echinodermata, Mollusca, Mollusca, Rhodophyta, and Tracheophyta

Temporal Coverage

Project Data

The Inventory of Seagrass Communities around Trinidad and Tobago was collected under the Coastal Conservation Project. Seagrass ecosystems are highly productive, faunally rich and ecologically important marine resources. They provide nursery habitats for a number of commercially important species, and their loss may significantly impact fisheries. Despite their tremendous importance, very little research has been conducted on these communities in Trinidad and Tobago, while they continue to decline worldwide. Studies on seagrass communities have been sporadic, and while some areas like Bon Accord Lagoon have been well studied, others have been overlooked. It is extremely important to methodically monitor seagrass communities around the islands so that changes in extent, distribution, density and species composition, whether positive or negative, can be ascertained. This data can then be used to facilitate sustainable management of the resource. Prior to designing and implementing a monitoring programme, an inventory of all seagrass beds around Trinidad and Tobago must be undertaken. This involves mapping the distribution of the existing beds as well as surveying the flora and fauna and determining the status of the beds. The Institute of Marine Affairs (IMA), as a component of its ongoing coastal monitoring programme, has conducted this inventory and presents the results in this document. The most extensive seagrass communities in Trinidad are along the northwestern peninsula: in Chaguaramas and Carenage Bay. In Tobago, extensive communities are found around the southwestern side of the island: in Bon Accord Lagoon, and from La Guira Bay to Canoe Bay. These beds, though healthy in some areas are showing signs of human impacts. Further research and monitoring are recommended so that they can be effectively managed.

Sampling Methods

Seagrass beds were mapped using information obtained form GPS (Global Positioning System) readings, aerial photographs (taken by Survair International Limited in 1994, at elevation 1,800m above sea level, at scale 1:12500; FS160, f/4.0), as well as visual surveys. Maps showing the location and extent of seagrass communities were produced using Arc Info Software.

Method step description:

1. Temperature, salinity, dissolved oxygen, and pH were measured at 1 m depth using a Sonde. Visibility of the water was determined by taking secchi disc readings. Total suspended solids concentration (TSS) was measured at 1 m depth at sites on the west coast of Trinidad. TSS was determined according to the gravimetric (difference) method outlined in APHA/ AWWA/ WEF, 1995. A known quantity of seawater was filtered through a pre-weighed Whatman glass fibre filter paper. The residue was dried for two hours at 105oC and re-weighed. Detection limit is 1mg l-1 Water nutrient concentrations {total nitrogen (TN) and total phosphates (TP)}, as well as Chlorophyl-a concentrations were measured at sites on the Northwestern Peninsula of Trinidad. Measurements were made once in the dry season and once in the wet season. TN and TP were determined according to methods outlined in APHA/ AWWA/ WPCF, 1995. Complexing agents were added to produce coloured complexes of each anion. Quantification of these anions was performed using UV/ fluorescence spectrometric analysis. Quantification of ammonia was performed using the method outlined in Grasshoff et al. (1983). Chlorophyll-a was measured using a method outlined by Strickland and Parson, 1972. Two-litre water samples were collected and the phytoplankton species were filtered onto a Millipore AA glass filter, using a vacuum pump system. Pigments were extracted from the algal cells by soaking in acetone over night, and then measured using a Perkin-Elmer 552A UV/VIS Spectrophotometer. Active chlorophyll-a concentrations (C) were calculated using Lorenson’s (1967) Equation.
2. Seagrass beds were visually surveyed and observations were made of seagrass and algal species composition, dominant seagrass species, and status of the seagrass beds using the following key: dense (> 10 shoots per 0.1 m2); sparse / sparingly (< 10 shoots per 0.1 m2); patchy (<5 shoots per 0.1 m2). The macrofaunal compositions of the seagrass beds were determined using a methodology adapted from English et al. (1994). A beam trawl (1.3 m wide, 0.5 m high, mesh size-2 inches) was towed behind a small boat over the seagrass beds. Tows were carried out for two minutes at two knots, parallel to the shore and opposite the flow of the surface current. The faunal species collected were counted, measured and identified as far as possible using identification keys. Plant species collected in the trawls were also identified using taxonomic text.

Bibliographic Citations

1. Juman, R (2006) An Inventory of Seagrass Communities around Trinidad and Tobago: Coastal Conservation Project. Chaguaramas Institute of Marine Affairs
2. Juman, R.A. and Bejai, M. 2008. Beam Trawl Survey of the Seagrass Community in William’s Bay, Chaguaramas. Institute of Marine Affairs"

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