//
archives

Catarina Silva

Catarina Silva has written 10 posts for oceanbites
Figure 1: The seagrass Posidonia oceanica © Carlos Minguell, Oceana

Long live the seagrass! The relationship between human disturbance and genetic diversity

The Mediterranean seagrass plays very important ecological functions but human disturbances are thought to be one of the main causes for its population decline. In this study, Jahnke et al (2015) try to understand how genetic diversity correlates with human disturbances and the results are surprising.

Figure 1: Changes in seawater chemistry from the 1800s to 2100 (projected) and impacts on marine calcifiers (organisms that deposit calcium salts in their body tissues) © Encyclopedia Britannica, Inc.

Like father, like son? Is survival under ocean acidification heritable?

Can marine life adapt to ocean acidification? Well, first we need to understand if these favourable characteristics (survival under elevated CO2 conditions) are genetically determined and can be passed on to the offspring!

The Chinook salmon (Oncorhynchus tshawytscha). Source: U.S. Geological Survey - http://www.usgs.gov/features/lewisandclark/ChildrenWebSites.html

Same species, different genes: temperature tolerance and body size in the genes of the Chinook salmon

To understand how species may cope with climate change we must look into their genes. Do individuals have different levels of tolerance to high temperature? What can genes tell us about it?

Figure 1: Octopus (Graneledone boreopacifica) observed by ROPOS during cable route surveys between Endeavour Node and the north Regional Circulation Mooring (RCM) instrument platform at Endeavour Ridge, 20 September 2010, at depth 2327m. Credit: neptunecanada

Supermom of the depths: octopus guards its eggs for the longest period ever observed

Scientists found an octopus that guards its eggs for the longest period ever recorded. The super mother was filmed for 53 months and has produced the largest and most developed hatchlings known to date.

The whale shark (Rhincodon typus). Photograph by Brian J. Skerry

Are whale sharks in trouble?

A recent study at the global scale suggests that there are two distinct populations of whale shark (Indo-Pacific and Atlantic Ocean). Authors show the evidence that populations of sharks aggregating at Ningaloo Reef in Western Australia have been declining in genetic diversity from 2007 to 2012.

Figure 1: Acropora millepora colony, Cattle bay, Orpheus Island, Great Barrier Reef (Copyright Vize 2009)

Coral larvae will stay at their birth reef in warmer seas

New research suggests that global warming is leaving large coral reef systems less interconnected, which can affect their ability to recover after disturbance and potentially deplete local populations.

Figure 1: Sea turtles incidentally caught by a fishing boat (© Projeto Tamar Brazil – Image bank)

Hotspots of unwanted catches: the global issue of bycatch

Incidental catches of nontarget species, also called “bycatch” have important ecological, social and economic impacts. A new study reveals the global distribution and intensity of bycatch of air-breathing megafauna (sea turtles, marine mammals and seabirds) and gaps in data availability.

Figure 2: Aerial view of the marine protected area of Torre Guaceto (www.pugliaevents.it)

The far-reaching benefits of marine reserves

It can actually work! A recent multidisciplinary study combining genetics and modeling conducted in the marine protected area of Torre Guaceto, Italy shows how effective marine reserves can be.

Figure 1: Merluccius merluccius (Linnaeus, 1758) photographed in Livorno, Calafuria by Stefano Guerrieri.

Not so alike after all: European hake populations might be locally adapted

Recent evidence that European hake populations might be adapted to local conditions (e.g. temperature and salinity at the surface) suggests the need to review current management strategies of their stocks.

Figure 2: Expected loss of alleles in the entire population (contour lines indicate proportion of alleles lost) in a species with discrete generations (a) or overlapping generations (b).

Plenty of fish in the sea? Appearances can be deceiving.

Overfishing reduces the ability to adapt in the face of change, even in highly abundant marine fishes.

oceanbites photostream

Subscribe to oceanbites

@oceanbites on Twitter