Dugongs are seagrass-dependent marine mammals found in tropical and subtropical coastal waters, broadly coincident with the tropical Indo–Pacific distribution of seagrasses. Their conservation is complicated by fragmented populations distributed over vast ocean areas, substantial changes in life history parameters associated with seagrass availability; high costs of real-time monitoring; and the small-scale artisanal nature of the gill fisheries which cause the greatest mortality.
Dugongs are vulnerable to fisheries, traditional hunting, large-scale losses of seagrass, smaller-scale habitat loss and boat traffic. Entanglement in fishing gear is the predominant threat as dugongs are by-caught in many kinds of fishing gear, in both commercial and artisanal fisheries. The threat is considered major, but the magnitude of the impact is largely unquantified in many countries.
But little reliable information documents these impacts, particularly because much of the dugong’s range is in developing countries which lack the necessary resources to conduct resource- and finance-demanding surveys. Knowing where dugongs are and what pressures they are under is critical for conservation, but documenting impacts form fisheries and distributions / abundances of dugong populations in a cost-effective and timely manner presents a unique challenge.
To address this, the Marine Research Foundation and a team of experts from around the globe developed a survey questionnaire which can be implemented at low cost and across large geographical areas. The survey is also designed to collect data on marine turtles and other cetaceans, and can be adapted to just about any marine or freshwater species.
The multi-disciplinary panel ensured that the survey design would be widely applicable across regions and issues, scientifically thorough and sound, and culture-sensitive. The survey protocols were then reviewed by a number of social science and bycatch assessment experts to determine language, appropriateness and scientific rigor. The questionnaire was then field tested in three countries and further refined prior to dissemination, and has undergone fine-tuning since it was first launched in 2010.
The questionnaire survey comprises 106 questions, of which the last six are internal questions to the interviewer which relate to interviewee confidence, knowledge and accuracy. These are used to provide quality control on the data sets. Questions address the personal background of the interviewee, the fishery (or other employment form), and numbers, trends, and locations of dugongs, sea turtles and other cetaceans. It also includes a data table for sightings of all marine fauna, which are drawn on to maps during the interview. This spatial component is one of the key strengths of the process, as it captures locations of fishing pressure and seagrass bed distribution. Interviewees each get a clean map on which to mark fauna records and their fishing areas, eliminating bias. Maps and sighting tables are linked by a code number to the questionnaire itself.
A standardized Excel spreadsheet was developed into which data are uploaded, with locked fields controlled via filters to minimize data entry error. Locked formula cells process the data in real time and construct 27 different graphic and numerical outputs in a standardized form, so that data are similarly interpreted from location to location. Graphic outputs relate to respondent demographics, fishing vessel and gear types, dugong numbers and trends, and perceptions of changes and importance of dugongs by the respondents. Users are unable to edit the graphs, but are able to copy their data into a new file and analyse separately / more thoroughly should they wish.
A ten chapter Project Manual was developed to explain the project rationale and introduce the CMS-UNEP Dugong Questionnaire Survey. It discusses such topics as interview methods and techniques, data integrity, survey design effort and efficiency, stratified and random sampling, field data collection and control, and how to link graphics to table data and survey numbers. More recent chapters address uploading graphics and spatial data and creating and exporting Google Earth layers to GIS, and basic GIS analyses once all data are uploaded.
The questionnaire was deployed in 18 countries spanning four key geographic areas (Pacific, Southeast Asia, South Asia and East Africa) with >6,000 respondents, and the results of the surveys provide the latest information on the distribution and abundance of dugong populations, while identifying and mapping areas of important dugong habitat such as sea grass beds, and assessing the relative risks to distinct populations from fisheries.
Given the nature of the questions and the variability in responses, potential bias and respondent misinformation, the programme is not envisioned to provide absolute numbers and precise locations of fishing areas and dugong hunting grounds. Rather, the questionnaire provides a rapid, low cost solution to dugong and fishery data acquisition which is scientifically robust, with a spatial analysis component which results in an identification of ‘hotspot’ areas where dugongs and fisheries overlap. These data along with the graphic outputs of the Excel sheet and the GIS analysis can be used to highlight priority areas for further detailed study and assessments.
This work was supported by the CMS-UNEP Dugong Secretariat and the Abu Dhabi Environment Agency.