March 26, 2003: Leg 3, Day #15
Today's update is provided by Rebeca Gasca from ECOSUR. Rebeca is one of the Mexican collaborators for the Gulf Expedition.
Soy Rebeca Gasca, la observadora mexicana
participante en este crucero, además
trabajo con los grupos de sifonóforos y anfípodos. Me siento muy
afortunada de estar aquí y tener esta oportunidad única de estar en un
barco con muchos de los instrumentos mas avanzados y sobre todo, el
sumergible ROV, que permiten estudiar organismos en su medio natural,
desde la superficie, hasta varios cientos o miles de metros de profundidad.
we traveled 48 miles to the south of Pescadero basin and headed towards
Alarcón seamount. As we dove, an echosounder registered the topography of
the scattering layer and, with the ROV
Tiburon, we went in search of the organisms that produced the
layer. Despite several attempts going up and down through the layer, which
was approximately 250–400 meters deep, we could not
identify the fauna. They seemed to be avoiding the vehicle. That made me
wonder how much else we are missing in this vast ocean when we are able to
look at it only in such small pieces.
I have seen living animals that before I
had only seen preserved. To see them alive has been breathtaking—I enjoy
watching the screens for hours with all that the ROV cameras are
registering, and as
always, I am looking forward to seeing them on board.
of the most interesting things that we have found (and one of my dreams
come true!) was a siphonophore of the family Rhodaliidae (see above and
left), probably Stephalia
corona. There are no previous
reports of this animal in Mexico, and it will be interesting to know (for
sure) who it is and more about its characteristics and distribution.
Some of these organisms are so fragile.
Just a touch with a finger would produce the disintegration of organisms
like Lilyopsis, the siphonophore found on one of the blue water SCUBA
dives. I wanted to include a photograph, but it disintegrated before we
could take one.
great thing for me was to snorkel in the middle of el Golfo (yesterday)
and to feel as small and as much a part of nature as all the brilliant
blue Sapphirina, stinging Athorybia
(a small siphonophore-see below), and bleeding (not really) Eurhamphea
ctenophores surrounding me.
came up early from today’s dive. We monitored the humidity increasing in
a major component of the ROV, the VME can. When it rose quickly from 15%
to almost over 20%, the pilots began to fear a leak, and we came up. So
far they have found water in one cable, which can be replaced. If they do
not find water in the can itself, we will be in the
water again tomorrow just a little later than usual. The pilots
are very good—some dives have been delayed due to equipment problems,
but we have always been able to dive and will keep our fingers crossed for
Agradezco a todo el personal del barco, tanto de la tripulación, como del equipo cientifico por las deferencias que han tenido para conmigo y especialmente a los Doctores Bruce Robison y Steve Haddock por invitarme a participar en este crucero que siempre recordaré como una de las experiencias mas enriquecedoras de mi vida.