Figure 1.
Globally reported Manta and Mobula landings were derived from the FAO Fisheries and Aquaculture FishStatJ dataset [36] by country (in metric tons). The relevant FAO species categories (“Giant manta” and “manta/devil rays, nei”) were pooled. An undifferentiated category of ‘rays, stingrays, manta nei’, was excluded from our dataset, because the proportion of mobulids in this category could not be estimated. No mobulid landings were reported prior to 1998. Note that other countries’ (Spain and Ecuador) reported landings were relatively small (<10t yr−1) and hence not visible at this scale.
Table 1.
eManta survey questions.
Table 2.
REEF diver observation data.
Table 3.
Life history characteristics for Manta spp. in comparison with other elasmobranchs.
Figure 2.
eManta diver survey effort with predicted occurrence of manta rays.
The number of participants (divers), and the total number of dives per cell across all participants are indicated by square (1–22 divers per cell) and circle size (200-62,190 dives per cell). Manta spp. occurrence as predicted from published habitat suitability models [22], is indicated by crosses. eManta survey consists of 90 cells from 373 participants and 616,498 dives.
Figure 3.
Global distribution and human use patterns from the eManta survey.
In general green indicates positive (large school sizes, increasing populations, ecotourism and no fishing or markets), red indicates negative (small school sizes, decreasing population sizes, no ecotourism and markets); a) school size (x = zero, red = 1–5, orange = 6–20, green = >20 individuals), b) reported change over time in school size (green = increase, red = decrease, orange = no change), c) ecotourism (green = present, red = absent, orange = combination where not all respondents reported the same observation, d) protective measures (green = present, red = absent, orange = combination), e) fishing (green = absent, red = present, orange = combination), f) markets (green = absent, red = present, orange = combination). Green crosses in b–f indicate cells with large school sizes (>20 individuals from 3a), black crosses denote cells where mobulids were not observed. Note that only some part of each cell may be observed.
Figure 4.
Fine-scale distribution and sighting frequency (SF) from REEF diver surveys.
Circle sizes are proportional to effort (number of dives). Grey circles represent sites where mobulids were never reported, green circles represent sites where mobulids were present at any time and blue squares show sites where >10 individuals were observed at any point during the survey period. In (a) Hawaii SF = <1–99%, effort = 1–949 dives; b) tropical eastern Pacific: SF = <1–86%, effort = 1–152 dives, and c) tropical western Atlantic: SF <1–24%, effort = 1–2,039 dives.