Halfway gone: endemic gorgonian Phyllogorgia dilatata is going bad on subtropical reef of the southeastern coast of Brazil

A study recently published in the Marine Pollution Bulletin describes the declined abundance and poor health state
of the gorgonian Phyllogorgia dilatata at Arraial do Cabo, southeastern Brazil. About 49% of the assessed colonies
were dead, and 75% of the living colonies were affected by tissue loss. These results are concerning because coral
disease outbreaks have long remained absent from Brazilian reefs. There is now mounting evidence, that this is no
longer the case. Further, P. dilatata remains as one of the last coral species providing habitat heterogeneity after the
loss of branching fire corals at Arraial do Cabo. Since reef fish diversity is correlated with habitat heterogeneity
these findings suggest further consequences for associated fish species. Colony abundance and health was
recorded at three different sites. Although we found significant differences among potential stressors, such as lost
and entangled fishing gear, the latter did not correlate with the overall decreased population health which was
similar among sites.

Hoping that all participants have learned and grown at various levels with all the symposia, workshops,
conferences, lectures and round tables available this year, everyone will be welcome again to the XXII Meeting of the
Brazilian Ichthyology to be held in 2017 in Porto Seguro, Bahia.

“There are three principal means of acquiring knowledge... observation of nature, reflection, and experimentation.
Observation collects facts; reflection combines them; experimentation verifies the result of that combination.” –
Denis Diderot.

Phyllogorgia dilatata at different health states. (a) Healthy: note intact laminae. (b) Diseased: note holes and
colonized skeletal axes (arrow). (c) Dead: note colonized skeleton. (d–f) Tissue purpling and formation of holes on
different colonies. Arrowheads indicate exposed, uncolonized skeletal axes. (g–j) Disease progression within 30
weeks on the same colony; note monofilament fishing line (by Gabriel Cassola).

Reference: Cassola GE, Pacheco MSC, Barbosa MC, Hansen DM, Ferreira CEL. 2016. Decline in abundance and
health state of an Atlantic subtropical gorgonian population. Marine Pollution Bulletin, in press. (disponible for free
download in the publications section)

Written by: Gabriel Cassola