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Delta Del Llobregat

Home Forums Field Trips & Conservation Delta Del Llobregat

This topic contains 44 replies, has 12 voices, and was last updated by  Matt 4 years, 11 months ago.

Viewing 15 posts - 1 through 15 (of 152 total)
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  • #300449

    Matt
    Keymaster

    Finally a continuation of this earlier thread. Since then some progress has been made and, thanks to Roberto, it looks like we have the chance to attempt an introduction of the fish early next year. *puts on S.E.I. spokesman’s badge* Now while we’re aware of negative aspects to introducing fishes to new habitats, not least those that have been spawned in captivity, this a special case in some ways. Before going on to explain, I should stress that none of the places in the images below are accessible to the public and special permission is required from the local environmental department. *takes badge off*

    This is the area around the pool which becomes flooded at certain times of the year.

    The water is fairly clear and the substrate is a heavy, clay-type soil. There’s no aquatic vegetation but presumably there’ll be plenty of algae during warmer months, and we spotted a few different types of aquatic invertebrate so there appears to at least be the potential to support life here.

    Attached files

    #315699

    Matt
    Keymaster

    Location 2 was near the beach and rather beautiful. The introduction of the fish here is still a fair way off as first they must prove successful at locality 1. There are no other fishes here as far as we could see.

    The water here was very clear indeed, basically as salty as sea water and the substrate mostly sandy. Most of the water you can see here is only temporary; the area to the right in the third image is the only permanently wet part.

    It was here also that Juan Pablo discovered we were eating in a Japanese restaurant later on.

    Onto Laguna de Ca L’Arana where again the plan might be to introduce the fish much later on. There was far less water here than last time:

    This is how it looked in September 2008.

    The freshwater channel that previously drained into the lagoon is now dry so the Gambusia that lived there are gone.

    The marginal vegetation was very sparse and we couldn’t find the Aponogeton species that grew here last year. Since that plant only grew directly in the outflow of the freshwater channel it’s easy to understand why.

    The lagoon is situated between a landing strip of El Prat airport and the Mediterranean, a typical location for many of Spain’s remaining coastal wetlands.

    Taking water samples. The specific gravity here was 1.029!

    Since that was a bit of a shock Juan Pablo decided to test the seawater which measured 1.030 or 1.031 (can’t remember exactly).

    Attached files

    #315700

    Matt
    Keymaster

    Our last mission was at Laguna del Remolar; it’s been surrounded by an electric fence since our last visit to prevent horses from crapping in it. This is the one that had me on my a**e twice. dry.gif

    The water level was lower here too, presumably a seasonal thing.

    The lagoon is split into two by a raised area, seen in the foreground here.

    …and as before no Aphanius were found in the larger, deeper part.

    Anyone know what this is for?

    Hard to believe this is the last remaining habitat of this population.

    Anyway while at first we couldn’t find anything our persistence was rewarded and we ended up with 8 females and 4 males (plus thousands of Gambusia) which believe it or not represents the most productive collection day this year. Sorry no good pics of the fish; hopefully I’ll be able to snag a better image from one of the others.

    Well that’s it, will keep this updated as things move on and hopefully we’ll get some interesting results.

    Attached files

    #315702

    Mark Duffill
    Participant

    Excellent stuff Matt, keep us updated Fish trap /wacko.gif” style=”vertical-align:middle” emoid=”:wacko:” border=”0″ alt=”wacko.gif” /> certainly is a strange one

    #315703

    mzapater
    Participant

    Hi everybody,

    The trap is intended to catch Pseudemys scripta. They stay on top to sunbathe, then the string is pulled and they fall into a net. Roberto told us that it´s proving quite succesful.

    The P. scripta get to breed in Barcelona, even Roberto gets some new ones in his garden every year.

    Thanks for letting everybody know about what we´re doing Matt, hope next year will be a good one for the project. And thanks a lot for your help!!

    Just a little question, the “reintroduction” of the A. iberus into these new lagoons has also the goal to stablish this particular strain, which seems to have some genetic differences with the northern populations (Estartit and so on), and also the southerns (Delta del Ebro, etc.), so it may be worthwile raising the numbers of them since their state at the Remolar lagoon is so critical now.

    Best regards,

    Manuel…

    #315704

    keith565
    Participant

    i have to second MD’s comments, well done guys. it’s heartwarming to see folk put in so much effort to help save an endangered species.
    i look forward with relish to see the next installment.

    #315724

    Plaamoo
    Participant

    looks like a great project guys! Very interesting, wish I was there to help! Thanks for sharing Matt and best of luck with the fish!! look forward to updates.

    #315736

    coelacanth
    Participant

    Have you got anyone who can do some proper invertebrate surveys? Would help in increasing the depth of knowledge on the various habitats, potential food items etc. etc.

    Are decent airguns available in Spain? In the hands of a good shot, they are pretty effective at getting rid of nuisance animals, including Pseudemys.

    #315737

    Eyrie
    Participant

    Very interesting to read about what you’re doing, and best wishes.

    #315750

    Matt
    Keymaster

    QUOTE (coelacanth @ Dec 14 2009, 04:05 PM) < {POST_SNAPBACK}>
    Have you got anyone who can do some proper inverebrate surveys? Would help in increasing the depth of knowledge on the various habitats, potential food items etc. etc.

    One of my main worries is about food sources especially at the latter two locations so I think this would be really useful. Any suggestions Pete? I did some entomology modules and field studies at uni but am by no means experienced. Presumably it’d be best to sample at various times throughout the year?

    QUOTE (coelacanth @ Dec 14 2009, 04:05 PM) < {POST_SNAPBACK}>
    Are decent airguns available in Spain? In the hands of a good shot, they are pretty effective at getting rid of nuisance animals, including Pseudemys.

    They are. Do you fancy a trip over? /smile.gif” style=”vertical-align:middle” emoid=”:)” border=”0″ alt=”smile.gif” />

    #315752

    coelacanth
    Participant

    QUOTE (Matt @ Dec 15 2009, 01:48 PM) < {POST_SNAPBACK}>
    One of my main worries is about food sources especially at the latter two locations so I think this would be really useful. Paul any suggestions? I did some entomology modules and field studies at uni but am by no means experienced. Presumably it’d be best to sample at various times throughout the year?

    Yeah, you need to talk to a Uni about this, I’d have thought that they’d jump at the chance to have some students doing work on an existing project. In the UK it would usually cost to get someone in to do an ecological survey and to be honest I’ve found them to be variable in the quality of what they deliver. Not sure what the situation is over there (there might be EU money available for this, it’s worth checking, alternatively talk to the local goverment people).
    Where Gambusia are present, it’d be good to get students working on gut content analyses, that should provide some useful data.

    Have you got this paper, BTW? Might be some useful information in there http://www.uv.es/see08/articulos/caiola%20…ologia_2001.pdf

    #315753

    Matt
    Keymaster

    Thanks some real food for thought there. The University of Girona have an aquatic ecology department and have done a few papers on Spanish species so will have a chat with Roberto; personally I think it’s definitely worth contacting them after the holidays.

    #317588

    Matt
    Keymaster

    Well the first 25 Aphanius will be released next Thursday (news piece dated 16/04). I’ll be accompanying Roberto to record everything.

    #317604

    keith565
    Participant

    wow, fantastic mate, fingers crossed everything goes ok.

    #317661

    Matt
    Keymaster

    Cheers Keith, it went very nicely indeed.

    Attached files

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