We had a very busy
Easter Sunday with three hauls taking place in one day. First was a deep water
haul, over 1000 meters deep which was landed on board at around 2am. From this
we sorted the blue whiting from the haul and measured and weighed the less
abundant, larger species. We then caught a few hours’ sleep before meeting at
9am to resume identifying, measuring and weighing the smaller, more numerous
species. Identification can be quite a difficult task due to the similarity of
some species who display only very subtle differences as their determining
feature.
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Deciding who's who. |
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Sorting the species... |
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... and finally some organisation. |
This haul contained
more interesting species compared to last year’s deep haul due to an increased
towing time. Included among the 30+ deep sea species were two deepwater spiny dogfish “Centrophorus squamosus” (one juvenile and
one adult female), five black scabbard fish “Aphanopus carbo”, a few snipe eels “Nemichthys scolopaceus” and many lantern fish species from
the myctophid family.
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Think we need a bigger board... |
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“Centrophorus squamosus” profile. |
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Black scabbard fish “Aphanopus carbo”. |
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Snipe eel "Nemichthys scolopaceus”. |
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Myctophidae 'lantern fish' species. |
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A tray full of horror - "Chauliodus sloani". |
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"Lampadena speculigera" |
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"Stomias boa" |
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A "Pseudoscopelus altipinnis" smile. |
Many of
these species contain light producing organs called photophores, these are used
for communication in the darkness of the deep sea and come in an array of
attractive colours!
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Blue on myctophidae species. |
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Pink on pearlside (Maurolicus muelleri). |
Even on
squid!
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Multicolour on unknown squid species. |
Haul 8 was
fairly standard mostly containing medium sized blue whiting. During haul 9 we
targeted a single dense school of blue whiting at around 550 m deep.
Unfortunately we just missed the main mark as little was seen entering the net
on the netsonde. Instead we used the time to trawl on a scattering layer at around
200 m which turned out to be mostly pearlside (Maurolicus muelleri). Despite the
near miss, haul 9 did contain a monster blue whiting of 42cm – not the biggest on
record, but not far from it! The large female deepwater spiny dogfish also made an appearance in haul 9 but
only as she had been stuck in the net all day, vouched by a crew member who saw
her while shooting the net earlier that day.
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Monster blue whiting. |
Part of
processing the blue whiting samples is to determine what sex they are, this is
important to understand stock health and productivity. In case you were
wondering what they look like, here you are!
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The females.. |
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..and the males. |
We are now steaming towards the start of our last transect before heading back to the Netherlands - hopefully we will be able to have our last and final haul during this time.
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