Evaluation of the Technique

5.3.5.1 Variables used in the Barbados experience and their application in a wider context

The variables used in this study are appropriate for the determination of the coastal sensitivity scale for Barbados. Making use of current background literature on the determination of CSI values has been an effective means of ensuring standardised evaluation. The shoreline descriptors (nature o f the shoreline, sediment grain size at the location, intertidal shoreline slope, and the shoreline wave exposure) are easily measured on-site. The items in Table 5.10 have been identified in order to perform the CSI analysis.

The results which achieve research objectives 1, 3, and 4 (Fig. 5.4a - d and Fig.5.5a - f), demonstrate that the variables selected can suitably define the CSI for coastal segments and suggest that the application o f these within a wider generic small island context can be easily achieved. The predominant factor in the establishment o f such scales relies on the ability to acquire the inexpensive scientifically accurate equipment. The methodology requires not only objective interpretation o f the physical characteristics, found on the coastline, and determining their relationship to existing environmental guidelines relating to shoreline oil spill sensitivity, but also a knowledge of the socio­

economic considerations of the “actual use value/ importance”. While this may be considered subjective, it can be verified by consultation with the appropriate agencies (both governmental and non-governmental), familiar with the areas. In so doing, a

“realistic level of value/importance” can be applied. Despite the author’s knowledge of the coastline, such consultation was performed here30.

Table 5.10 Main Equipment Items Used in the Determination of the Coastal Sensitivity Index

EquipmeiiiItem Accuracy

100m open reel fibreglass tape +/- 2mm

♦Automatic level +/-1.5mm

♦Total station +/- 0.2mm

Fibreglass tripod

6 sand sieve set According to the mesh size required

Sand sieve shaker

Ohaus Scout 2 portable electronic balance 200g x O.Olg

Brunton ClinoMaster +/- 90°

Scale master Classic +/- 25 % (resolution 1mm)

Stereoscope (small mirror)

Table notes: The items used in the determination of the beach slope (e.g. telescoping rod) and wave exposure indexes has already been identified in Section 5.2.5.1, and are therefore, not repeated here.

5.3.5.2 Data Availability

The data used in this component of the research have demonstrated their applicability and ease of availability. Past work focused primarily on the generic description of the shoreline and related this to the shoreline oil spill sensitivity characterisation, as identified by NOAA (1997) (Anthony Headley, pers. comm. 2001). The results have fulfilled research objectives 1 and 3 (Section 1.3.2).

Fisherfolk Association, Oistins Fisherfolk Association and Barbados National Union of Fisherfolk Associations.

5.3.5.3 Economic Costs

The economic cost of this technique includes the actual cost of equipment, transportation to site and man-hours for collecting the data (Table 5.11). Although the equipment costs approximately GB £7,374 (US $12,036)31 this cost could have been reduced with a less costly levelling instrument. The recommended purchase of a Pulse Total Station costing GB £6,162 (US $9,990) is based on its level of accuracy and ability to retain large series of data points for future data processing. An alternate instrument, a SAL 24 automatic level costing GB £263 (US $429), would have meant the manual recording of data on field sheets, only allowing one record of the field data.

The first instrument allowed for the ability to recheck data obtained from the field in case of transcription or transposition errors in field recording. The purchase of the field equipment plus the alternate meter is GB £1516 (US $2475). The saving to be made if the alternate meter was purchased is GB£ 5860 (US $9561).

Transportation costs have been previously considered in Section 5.2.5.3. Man-hour costs and the training cost reported here are based on the rates characteristically paid to the CZMU field staff, previously quoted at Section 5.2.5.3.

5.3.5.4 Logistics and Administration

The greatest difficulty associated with this technique is the determination of appropriate measurement locations. For Barbados, the beach profile locations predetermined the selection of monitoring sites for this index. The rationale for the location selection is previously described in Section 5.2.5.4. However, the sites chosen allow for returning in the future, to perform the biological assessments to describe the full environmental sensitivity of these locations.

In island situations where these sites do not exist, it is necessary to either establish bench-mark locations for the long-term monitoring or use GPS systems to allow for a

return to the same position. The associated requirements for consideration in such situations are discussed in Section 5.2.5.4.

Table 5.11 Cost Associated with the Determination of CSI (indicated as Man Week Costs)

AsSkaftz

Determination o f Coastal Sensitivity Index

Number o f staff (weekly rate) & staff time (days) required to determine Coastal

Sensitivity Index

♦Refer to Appendix 5 Table IQ for equipment listing. However, the cost with (1) the automatic level, and (2) the Total Station instrument are reflected separately to show their effect on total costs.

** Man week costs are salary rates based on current Government monthly salary scales for the positions of Chainman (for field data collection) and Clerical Officer (for data processing), as these are the level of staffing required to perform these works. These costs are not included since they have been quoted previously and are weekly rates.

*** Costs not included here would be the purchase of direct capital costs (e.g. computer hardware (including colour printer and incidentals for computer usage) and associated software (Microsoft Office Suit and SPSS).

5.3.6 Recommendations

In addition to the foregoing, it would be instructive to include relevant biological information associated with each coastal habitat. This might be achieved through the determination of foreshore sensitivity criteria as identified by Abdel-Kader et a l (1998) or Nansingh and Jurawan (1999). Emphasis would have to focus on flora and fauna as the NOAA Guidelines (1997) suggest. However, the broad classifications, while applicable to Barbados, do not hold true everywhere32. This recommendation provides for future work in identifying other habitats in need of protection, as only the immediate nearshore habitats are considered here.

Human use features encountered along the coastline can also be mapped and included.

In this thesis the human use component was captured as part of the five criteria in the sensitivity criteria table, described previously (Table 5.7a). However, the main human use features of the study area include those that can be impacted by an oil spill or could provide access for clean up operations33. Although these have not been separately accounted for, these features could be incorporated into the CZMU GIS34.

If this approach were extended to encompass the entire island, new categories would need to be developed to address the contrasting shoreline geomorphology and nearshore habitats along the east and southeast coasts (Figure 2.3). Such modifications could result in a new ranking for the island’s habitats.

32 Barbados has no relevant coastal bird population so emphasis in this area would have to focus on the migratoiy bird species, known to frequent die island annually, as part of their migration route. There are no mammals that use the nearshore habitats. Additional consideration should be given to including information, where appropriate on shellfish and marine reptiles. Regarding the fish species associated with the coastal habitats it can be envisaged that the reef fish found at each location would constitute the major fish species to be found.

33 Refer to NOAA (1997) for a listing of the types of features to be considered for inclusion.

5.3.6.1 Modification of the Technique

The CSI technique has successfully demonstrated its usefulness as a rapid approach to determining the environmental sensitivity of the shoreline to oil spill pollution.

Modifications should include the ability to identify total lengths of coastal types susceptible to oil pollution. This could be calculated from the percentage of the shoreline affected and its vulnerability score. These could then be presented as an applied oil spill vulnerability index for the shoreline type. Additionally, it could be used to determine the percentage of the shoreline, classified according to the relative vulnerability index levels and, hence, their classification according to their susceptibility to oil spills.