Monday 13 November 2017

Hits and Misses


tritonia odhneri in 2007
errina antarctica 2017

It’s with a feeling of relief that I’ve been able to remove a glaring and prominently placed mistake in one of my previous Blogs. I was feeling quite happy with my blog-writing ability, having a bit of a swagger about being able to bring some of the underwater creatures to ‘life’ for some folks who have never encountered them before.

I’ve now removed that source of embarrassment. No need to say more (particularly if you hadn’t noticed it!)

The ability to make huge errors is never really vanquished. Particularly in a Blog … we rarely have more than an hour to write these. And we both check them over – but we rarely seem to catch the big errors when we proofread each other’s blogs. Possibly Larry has an exaggerated idea of my writing ability because he sees me reading and reading …

errina antarctica fan coral 2007
I’m also very much aware that without a ‘real’ biologist’s skills and tools for dissecting and closely examining the animals, I can very easily be wrong in the identifications and information I give here. Also – with new discoveries in research, my ageing books and information may now be out of date. Even with Larry’s help in checking the data, there’s a huge margin for error.

The temptation to assign a cause for missing animals we saw 10 years ago would be very wrong. For one thing, we are not experienced specialized divers so we may just not have seen what was plainly there to be seen. In fact, I was brought to an awareness of my own deficiencies as a diver when I read David Behrens statement in ‘Pacific Coast Nudibranchs’ that “on a single dive, the inexperienced observer should be able to find 6 to 12 species of opistobranchs without too much difficulty”.
sunflower star - in British Columbia 2014
We rarely find more than 2 species. Also - the fact that we missed seeing any of the spectacular orange tritonia odhneri nudibranchs could be because 9 years ago we saw them in the middle of summer (January 6, 2009) and it’s still too early in spring. Or that their primary food source (the octocoral fan errina antarctica) didn’t seem as flourishing as on our previous trip.

latruncullia ciruela a new type?
Behrens shows several other reasons for our disappointment. One is as follows: “Many species have been observed to come and go from local habitats, disappearing for years at a time where it was once abundant, and then reappearing once again … biogeography is one of the most speculative aspects of the biology of organisms.” So the fact that we didn’t observe the the orange nudibranch may just be one of environmental fluctuation rather than loss. Similarly, one hopes that the same reason can be attributed to the losses of beautiful sunflower stars (pycnopodia helianthoides) in British Columbia and Washington.

latruncullia ciruela sponge
Some of the wonders of the trip have been that - with the help of the ‘Benthic Fauna’ book - we’ve seen some new animals and been able to properly identify some whose picture we took 8 or 9 years ago and could not identify earlier.

Newly identified for us: latruncullia ciruela.



No comments:

Post a Comment