contrasting case studies

contrasting case studies

1. LORD HOWE WOODHEN

   • ISLAND - 1969 - 20 TO 25 bird, 6-10 breeding pairs. too low, needed to take action. 1980 3-6 breeding pairs, restricted to upland sites. Possible problems...
     • too few nest sites
       • wasn't the problem - there were lots of burrow they just weren't using them
     • too little food
       • abundant food in uplands and lowlands
     • introduced black rats
       • most abundant where woodhen still present
     • introduced cats
       • ate rats and seabirds, not woodhens
     • introduced tazmanian masked owl
       • couldn't catch woodhens, no evidence they were eating them
     • introduced pigs
       • did not overlap - indicates might be a problem. competing for food (petrels) and pigs thought to eat woodhens too
         • put a bounty on pig tails - eliminated ferel pigs from the island. wasn't enough, needed to do captive breeding to help the population. by 2000 - 40-60 breeding pairs. maximum number habitat can support
     • systematically looked at these problems to see which was causing the declines

2. New Zealand Kakapo - 1990 less than 50. eggs and chicks eaten by introduced predators. rats and stoats were eradicated from 2 key islands

   • captive breeding program with artificial insemination. shy and reluctant to breed, took a long time to work

3. aruba island rattlesnake

4. abutilon pitcairnense

5. lord howe island stick insect - bills pyrimid. thought extinct. 1930 found under 30 on bills pyrimid - captive breeding

6. seychelles sheath tailed bat

7. BLUE FIN TUNA

   • population has been reduced to less than 15% - problems in conservation - all related to money and politics
   • In 2009 - they were allowed to fish 19, 905 tonnes of fish every year. - population plumeting. scientists recommended suspension of catch
   • ICCAT stalled - sole purpose is to protect tuna... so CITES set up in europe. US didn't back CITES for financial reasons
   • ICCAT reduced quota to 13,500 tonnes, not enough but the best they could do. this was consistently exceeded - so nothing changed and catch was still ~ 20,000 tonnes
   • Tuna is a massive business - worth £4730/kg in 2013.
   • italian fisheries minister wasn't happy - placing a ban on fishing for 3 yrs is like getting rid of it forever. but we are already getting rid of it forever fishing in this way
   • 2010 - greenpeace denounced spain for trying to get EU not to support international trade ban
   • TUNA TIMELINE
     • 1960s - juvenile blue fin tuna fishery emerges.
     • 1966 - ICCAT
     • 1960S - 1979S - Lots of fisheries develop - for adult blue fin
     • 1980s - spawning stocks decline
     • 1982 - 1997 - harvests of bluefin restricted
     • 1998 - ICCAT adopted program to rebuild fish stocks
     • ICCAT didn't implement this plan until 2006
     • 2007 - US and others fail to seek suspension on bluefin tuna fishing
     • been going on for 30 years and nothing is being done about it
   • a lot of conservation in europe is terrestrial
     • 2008 - scientists recommended the establishment of 127 marine conservation zones
       • by 2013 only 27 had been set up. and were smaller than suggested
         • 2015 - 23 more announced. really dragging heals on marine protection. since economy crashed not a priority. economics and commercial gain is getting in the way of conservation

8. CONSERVATION AND FOOD SECURITY

   • Worried the population won't be able to be fed.
     • attempt to reduce herbicides, pesticides etc.
       • good for poorer parts of the world where they can't afford these.
         • east african crops like maize, sugarcane, millet, sorghum - found a more natural way of protecting crops from moths and parasites
           • underplant with desmodium - in amongst the maize crop - napier grass gets planted in blocks around the crops - plants produce chemicals against pests - they also attract pollinators
             • napier grass produces sticky secretion that kills 80% of stem borer larvae - so if they try to eat the plant they get killed
             • on top of that desmodium - shades the soil, adds nitrogen and chemically inhibits striga
             • and you can feed these plants to livestock
             • 7 fold increase in yeild, long term increase in soil fertility. native plants - no invasion. collaboration between UK and African scientists

9. asian white backed vulture - eat cattle treated with diclofenac. causes kidney failure in vultures

   • 2007 - 99.9% population decline
     • many countries banned the use of vetinary diclofenac
       • down 50% - vulture pops slowly recovering