The literature indicated that seaho

The literature indicated that seahorse density tended to be low and that they
were patchy in distribution (Table V). For example, H. guttulatus mean density
was generally 0
07m2 (range 0 to 0
51m2), but reached 10m2 in small
patches on the edges of seagrass beds over a transect survey covering
3324m2 of the Ria Formosa Lagoon, Portugal (J. Curtis, unpubl. data). Likewise,
H. whitei were found at a density of 0
08m2 in one area of seagrass in
Sydney Harbour, and 0
215m2 in a very similar patch of Posidonia and
Zostera seagrasses only 20m away, with no other seahorses for hundreds of
metres around (Vincent et al., in press). Given the variation in seahorse
densities, it is important to document and assess the manner in which seahorse
population densities were extracted: bias in site selection means that they were
likely to be greater on focal study grids than in transect surveys. For example,
H. capensis were recorded at a mean density of 0
22m2 on a focal study grid