IMIS

Attempts were made to contact at least 5 experienced divers (>200 dives in the area) for each area of the known distribution of Manta rays.
The survey was distributed through available social-media outlets and diver organizations, and by contacting dive shops directly, focusing on the 173 spatial cells where manta rays are predicted to occur according to published species distributions on Aqua Maps (Kaschner et al 2010). We sent personal emails and phone calls to divers and dive shops in every cell possible, as identified from a Google search using land or sea features labeled on Google Earth within the cell (i.e. “Location”, “Dive Center” or “Diving”). We aimed for 5+ contacts per cell; however, 40 cells had fewer than 5 available contacts and 55 cells had no contacts listed or no mapped features that could be identified. Therefore, we sent survey requests to 125 cells, 85 of which had at least 5 contacts. Live-aboard dive boats and dive clubs were also included.
For each survey, divers were asked to select the cell, from a global map displaying all 648 possible cells, where they have logged a minimum of 200 dives and to summarize their dive effort and observations for that cell. As such, the survey was restricted to experienced divers who have typically logged thousands of dives in a particular area, and are familiar with local wildlife. Ward-Paige et al, 2013 contains the list of questions asked that were relevant to this study. Data were summarized by cell and mapped at a 10×10 degree resolution. For each cell we calculated the number of records (i.e., participants) and dives (i.e., sum of all dives across all participants), median presence and absence of mobulids, average maximum school size excluding zeros, and median observed change in maximum school size (increase, decrease or no change) across all records. As for human uses, we mapped the median reported spatial extent of ecotourism, protective measures, fisheries that were observed to catch mobulids, and their occurrence in local markets. The survey records contain the cellID associated with the 10x10 degree grid. Each cell was assigned minimum and maximum latitude and longitude coordinates. The mid point coordinates was chosen as the nominal position for the DwC record and coordinate precision was set as 5 degrees.
Scientific names associated with resource occurrence records have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS). The WoRMS codes, the AphiaIDs have been included as LSIDs in the occurrence record DwC field scientificNameID. Locations were plotted and positions checked to see if on land.
The original data records collected as part of the survey are archived in OBIS Canada folders and with eShark. The OBIS view of this survey dataset does not include any information that could directly identify the survey respondent or the precise area where they dive occurred or where animals were observed. The only information shared with OBIS at this time is the presence of manta or mobulids in the 10x10 degree grid cell. Darwin Core (DwC) records were created and a new DwC BasisOfRecord vocabulary term was assigned - instead of 'human observation' the phrase 'local knowledge' was assigned. The sampling protocol field clearly indicates that this is a citizen science project and the recorded by field provides information related to the divers experience (number of years diving, etc).
Users should contact eShark.org if they wish to access information contained in the original survey dataset.