And talking of those Pelagic Threshers.
I really did like this.
Monad Shoal close to Malapascua Island is where divers get to experience those Sharks being cleaned, whereas they have been filmed hunting at Pescador Island.
Enjoy!
Blog about "The World's best Shark Dive" by Beqa Adventure Divers. Featuring up to eight regular species of Sharks and over 400 different species of fish, Shark diving doesn't get any better!
... countries are beginning to put measures in place to increase the sustainability of their shark fisheries, and research is constantly being done to further their efficiency.
In my opinion, it is the development of these biologically based, best practices, concerning reproductive traits and ecology of shark species which hold the greatest potential in minimising shark stock collapses and population declines. Fragmenting the conservation effort by targeting single practices (such as implementing shark finning bans) can obstruct the development of more effective shark management tools.
Abstract.
(...)
PERMANOVA analysis showed that over-exploited and depleted fisheries employed different sets of measures than fisheries with healthier stocks, and a non-metric multidimensional scaling ordination illustrated that a broad set of regulatory measures typified sustainable fisheries.
SIMPER and regression tree analyses identified that the dissimilarity was most related to enforcement capacity, number of species harvested, fleet (vessel) controls, limited entry controls and rotational closures.
The national Human Development Index was significantly lower in countries with over-exploited and depleted fisheries.
Where possible, managers should limit the number of fishers and vessel size and establish short lists of permissible commercial species in multispecies fisheries. Our findings emphasize an imperative to support the enforcement capacity in low-income countries, in which risk of biodiversity loss is exceptionally high. Solutions for greater resilience of XYZ stocks must be embedded within those for poverty reduction and alternative livelihood options.
Trends in sustainability and exploitation
(...)
Management measures
Enforcement (and compliance) capacity varied greatly among fisheries and tended to be weak in tropical fisheries in low-income countries.(...)
The PERMANOVA contrasts showed that, in terms of variables potentially controllable by the fishery manager, under-exploited, moderately exploited and fully exploited fisheries were similar, but differed significantly from management variables employed in over-exploited and depleted fisheries. The subsequent SIMPER analysis identified that enforcement capacity was the management tool most strongly related to the dissimilarity between unsustainable and sustainable fisheries.
Nonetheless, other management variables were also important and contributed only slightly less to the dissimilarity than enforcement capacity. Specifically, the other management measures important in the majority of difference between sustainable and unsustainable fisheries (in descending order of importance) were the following:
- fleet (vessel) controls,
- limited entry controls,
- rotational harvest closures,
- the total number of species harvested by fishers,
- licensing and reporting requirements, and
- the number of regulatory measures used by the manager
Discussion
We aimed to relate management measures to sustainability of XYZ fisheries, and our analyses indicate that resilience of social-ecological systems (SESs) of XYZ fisheries will come from strengthening enforcement capacity, allowing only a small number of species to be harvested, applying input controls, reducing the number of fishers per unit of fishing ground and improving the socio-economic state of human communities. (...)
Stocks of commercially valuable species have been depleted at a comparably fast rate over much of their distribution. Many XYZ species face a high risk of extinction through overfishing coupled with inherent biological and ecological vulnerability. Apart from an unlikely reduction in demand from Chinese consumers, we believe that sustainability and resilience of troubled XYZ fisheries will only come from the adoption of radically different approaches to management.
Enforcement drives sustainability
While marine reserves, international trade agreements and stock assessments may be important tools for sustaining XYZ stocks, our analysis highlights the importance of enforcement capacity in fisheries sustainability.
Indeed, many fisheries struggle with deterring fishers from illegal activities by compliance measures or strict penalties. The SIMPER and RT analyses both indicated that depleted and over-exploited XYZ fisheries predominantly had weak enforcement capacity. Thus, fine-tuning management regulations or developing complex management plans are less likely to succeed in protecting minimum viable populations of XYZ than investment in compliance and enforcement. (...)
Conclusions
Stocks of commercially valuable species have been depleted at a comparably fast rate over much of their distribution.
Many XYZ species face a high risk of extinction through overfishing coupled with inherent biological and ecological vulnerability. Apart from an unlikely reduction in demand from Chinese consumers, we believe that sustainability and resilience of troubled XYZ fisheries will only come from the adoption of radically different approaches to management.
Recent assertions about improved management of XYZ fisheries have centred on regulatory measures and management actions, marine reserves and international regulations, research, monitoring and harvest strategies.
Our findings reveal that a new paradigm is needed for managing XYZ fisheries; one in which resources are shifted from the development of complex management plans to enforcement and compliance of simple sets of regulations and to tackling the socio-economic challenges of coastal fishers that transcend fisheries.
The best devised management plans will fail if disincentives to illegal fishing activities are not strong enough and/or if underlying poverty of fishers is not improved. We also conclude that multiple management measures are needed in XYZ fisheries but not so many that they cannot be easily understood and enforced.
In addition to compliance and enforcement, the key regulatory measures appeared to be the following:
Evidence of slow growth, low natural mortality and high longevity in some species underscores the need for more conservative management strategies than in the past and cautions the use of conventional fisheries science underpinned by estimations of maximum sustainable yield.
- a small list of permissible species for exploitation,
- fleet controls, especially on the size of boats in the fishery,
- limited entry controls to restrict the number of fishers, and
- licensing and reporting requirements.
The great variation in the scale of fishing activities, management systems and technical capacities of management bodies means that multiple, country or region-specific solutions will be needed to redress the shortcomings in collapsed fisheries.
Operationalizing an ecosystem approach to fisheries management (sensu Garcia et al. 2003) requires a greater involvement of stakeholders, consideration of alternative management systems and a higher priority of social science in management institutions.
Resilience in XYZ fisheries will come about only if fishers are part of the management system and can adapt quickly to changes in the resource. In the vast majority of global fisheries, regulations towards sustainability are commonly undermined by political pressures (Mora et al. 2009).
Transformation of the management paradigms currently undermining XYZ stocks, therefore, inevitably needs to be supported by decision-makers resolutely if these animals are to remain valuable to the livelihoods of coastal peoples and provide the eco-services that contribute to healthy marine ecosystems.