Tag Archives: Habitat

Where the wild things roam: Dispersal, connectivity, marine protected areas, and my PhD project

 

In my last post I mentioned that I am starting a PhD.  I promised to tell you a little more about what my research will be looking at, so here we go!

The project outline

My research comes very broadly defined already – the work’s raison d’être if you like.  Here it is:

“Movement and dispersal connects marine populations, allowing restoration of depleted local populations by immigrants that renew genetic diversity. Although Canada’s Oceans Act prioritizes ‘linking Canada’s network of marine protected areas (MPA)’, connectivity has not weighed significantly in MPA network design in Canada. This study will optimize regional marine connectivity among protected areas in the Atlantic region by determining optimal locations for new MPAs and evaluating how commercially important species would be representative in the entire MPA network. To model species distribution based on larval dispersal, fishery pressure, and climate change, we will use 3-D ocean circulation models. Then, based on metapopulation theory, we will develop novel spatial network algorithms to optimise the number and spatial connectivity between MPAs under current and future scenarios of climate and fishery pressure that may alter larval supply”.

Sounds complex?  Yep, for me too. Continue reading Where the wild things roam: Dispersal, connectivity, marine protected areas, and my PhD project

Protecting Kenya’s dolphin habitat

Marine protected areas (MPAs) are pretty nifty tools for marine conservation. You take an area, you give it a designations and (hopefully… but the reality can be quite different) you attach some regulations/legislation to remove harmful activities to whatever it is you are trying to protect inside the MPA and make efforts to rebuild and conserve this spot. The situation of picking an area to designate can become trickier when dealing with ocean wanderers – species that move around a lot, and over great distances. It is safe to say that it is politically unfeasible to designate one area big enough to encompass, for example the movement of sea turtles. Instead, sea turtles may find critical habitat – feeding areas or nesting beaches for instance, covered by an MPA. We can’t protect them everywhere, but we can build a case to protect them where we know they hang out in large numbers. Some species are a little less predictable – or we simply don’t know where their critical areas are. Take southern Kenya’s populations of Indo-Pacific bottlenose dolphins (Tursiops aduncus) for instance. Apparently these critters are the most abundant of the marine mammals in Kenya’s Kisite-Mpunguti MPA. Abundance does not mean we know much about them though. The species is listed as data deficient on the IUCN Red List. Continue reading Protecting Kenya’s dolphin habitat

The ocean moves – and so should marine conservation management

A casual glance at the ocean and you may just see a mass of blue.  But take a closer look.  There are waves, different colours, and different levels of water clarity.  If you could peel back the layer of water, you would see environments that are not entirely alien – like mountains, canyons, forests, grass meadows, sand, mud, and volcanoes.  The ocean is a mosaic of the most wondrous and splendid habitats, hosting a magnificent array of life.  Whilst the terrain itself may remain fairly stable, the ocean itself moves.  It’s not just the waves you can see breaking on the beach, nor the movement of the tides, or even those rip currents you really don’t want to find yourself stuck in.  Beneath the surface, you will also find movement like currents flowing at different depths, upwellings that bring cold, nutrient rich waters to the surface, and internal waves as tall as 244 meters.  Sometimes you get two water masses moving either towards or way from each other, creating oceanic fronts.

Broadly speaking there are two types of oceanic fronts.  Convergent fronts occur when the masses move towards each other.  Here the water tends to be warmer than the surrounding area, and accumulate all sorts of marine critters, algae, and even litter.  In divergent fronts, where the water masses are moving away from each other, upwellings are created bringing up nutrients from the deep.  These nutrients support phytoplankton growth, which in turn supports zooplankton, which in turn supports other marine life – including species under threat, and species we like to eat.  The thing about fronts (as with many oceanographic features) is that they are not necessarily permanent features that remain in the same place.  The ocean is dynamic and as a result the habitat for many critters that live in the water column is also dynamic.

Continue reading The ocean moves – and so should marine conservation management

Sawfish living on the edge

Folks, I’d like to introduce you all to sawfishes (not to be confused with the similar looking but very distinct sawsharks). There are 5 recognised species that make up this family of rays (the Pristidae ), all of which are ‘of conservation concern’. And when I say concern, I really mean it. Three of the five species – smalltooth sawfish (Pristis pectinata) , largetooth sawfish (Pristis pristis) , and green sawfish (Pristis zijsron) are classified on the IUCN Red List as critically endangered. The remaining two species – narrow sawfish (Anoxypristis cuspidate) , and dwarf sawfish (Pristis clavata)_ are classified as endangered. These rather beautiful rays, argues Nick Dulvy from Simon Fraser University and collaborators from Australia and America, are probably “ the world’s most imperilled marine fishes ”. Like other rays, and indeed sharks, skates and chimeras – all of which are a class of fish called Chondrichthyes – the cartilaginous fish (their skeletons are made of cartilage not bones), sawfish conservation has not been much of a priority in most areas of the works. Fortunately for sawfish, not everyone thinks that this is right, so Nick and his team of collaborators have put together this neat paper summarising some key informationon sawfish to help get the ball rolling a ‘tad’ faster than it is already. In fact the information summarised in this paper has played a part in the Global Sawfish Conservation Strategy. So let’s take a peek into the world of the sawfish, and crucially what we can do to give them a chance.

Continue reading Sawfish living on the edge