Fisheries Sustainability - Science topic

First, the ways in which indigenous people interact with natural resources and the extent of their utilization of natural resources need to be analyzed using ANOVA statistical analysis. These outputs needs to be elaborated to evaluate the necessity of measuring the readiness from indigenous people. Hope this answer helps.

Can you be more precise: what hydraulic circuit do you refer to, and what type of development you are referring to?

Minimal water use aqua-systems, multi-trophic aquaculture, climate smart aquaculture, biofloc, feed preparation with local ingredients (insect meal), brood stock feed, genetics in aquaculture, waste reduction, biosecured aquaculture, live feed production, aquatic ornamental plant production etc- are currently given much importance in India.

Dear Taylor, the group of Robert Arlinghaus (Berlin) has done a lot of research in this field. You may contact him and/or check his reference list here on ResearchGate.

Best regards, Klaus

In general, discards are not of the target species. If this is your case, you can be sure to apply stock assessment methods with landings of your target species. The problem will arise if this fishery are discarding the species target. I believe that, in this case, you should estimate the discard proportion and explain this clearly when runnig your model.

Gareth,

I agree that it is a difficult question that needs to be addressed, and I think it is being addressed in many areas. My personal interest is in aquaculture of species at the bottom of food chains that can be fed without degrading wild fish stocks that are at the base of marine food chains that ultimately support wild fisheries. Moving the coastal salmon pen aquaculture into land-based operations could address the pollution and parasite issues associated with the industry, and finding suitable food source other that so called marine trash-fish (which are needed b wild fish populations)  would be a step in the right direction.

Tomas

Dear Alex, usually local policies are more restrictive that regional or national ones. I do not know how it works for EU countries, but for sure if you have local rules, they need to be followed. Otherwise you can check local guidelines for fishery, whether available. 

Fish production demand is continuously increasing. What is your opinion about high density production system using recirculating water or zero discharge system

2J3KL northern cod though a fishery dependent index. Lots of good paper by Myers, Hutchings, Walters and others on it. You could argue that almost all assessment use poor indexes since we do not actually know if they are proportional to abundance. There are a few salmon cases where we actually know. I think the P. hake acoustic time series was thrown out due to poor ground-truthing but it would be tricky to connect the index in the assessment to the management decisions made. There are a number of issues with the indexes used in the tuna assessment due to standardization problems. Would also be difficult to make the connection between these and the management advice.

Thank you Nirmala. 

The article that I provided a link for compares CTA with some of the most popular legacy “multivariate” procedures (to be precise, multivariable describes methods involving multiple independent variables), including logistic regression, SVM, and random forest models. Those who read the article (or, minimally, read its abstract) will learn that the CTA model was not only most accurate, but was also most parsimonious. This is no surprise—articles in many fields of inquiry have reported models achieving greater accuracy and greater parsimony using CTA than models obtained using legacy multivariable linear models (and never reported the opposite finding).

If the underlying most accurate and parsimonious model *is* linear, then CTA will find it—however there are examples in which CTA identified a more accurate and parsimonious linear solution than the legacy method. However, if the underlying most accurate and parsimonious model is non-linear, then only CTA will find it.

Indeed, the univariable (also known as bivariate) method that I also cited has been used in numerous articles to adjust the decision thresholds used by legacy linear multivariable models in order to explicitly maximize their predictive accuracy. In all cases that I am aware of this “refined” legacy model is more accurate than the original solution, and this boosted performance has been shown to hold-up in cross-validation. There are plenty of articles on these subjects available at no cost in a free eJournal (www.ODAJournal.com), and the Publications tab on the eJournal webpage lists plenty more such articles in pay-for-view journals.

With respect to size class, I use mass weighting to maximize the ability of the model to predict success of different methods with respect to catching (in particular) large fish. This is because I hunt for world-records (individual fish)--which are based on weight (mass). Commercial fishermen hunting for sushi-grade fish are also interested in catching massive fish: those seeking fish for cat and dog food, and “canned tuna” for supermarkets, target small fish species (e.g., skipjack,  bonito, albacore)--and routinely catch as many fish as possible (all elite sport fishermen that I know strongly oppose this "clear cutting" practice that destroys local fisheries). If instead one wishes to weight by length (when tuna boats don’t have an on-board scale, the methodology for estimating weight involves a formula that includes length and girth as variables), or by age (a less precise measure than mass, age can be used as an independent or a dependent variable, and mass weighting can still be applied)—then one simply uses the desired index as a weight. To my knowledge only fishermen hunting muskies typically report the length of the fish, and sport fishermen hunting bluefin tuna sometimes report length (the commercial fleet reports weight). While I have nothing against small species--and also seek world records among such species (came within ounces with yellow perch), they are more difficult to catch because in fishing grounds that I visit the various sizes (ages) within a species tend to school (or to homeguard local structure) together. For example, to get to a large female snook one must first go through an army of smaller males.

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For those desiring to learn various legacy multivariable and multivariate (multiple dependent measures) methods--requiring greater mathematical and programming savvy to master than the optimal (maximum accuracy) data analysis (ODA) paradigm, I recommend the following two best-selling introductions that are available at thousands of academic libraries--as a starting point:

Repeating my comment in another thread, a caveat is that a major problem with legacy methods is inherently faulty assumptions, and a major shortcoming of research practice is failure to evaluate one's assumptions.

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Learning the bivariate method that I specifically mentioned to address the design described in this thread requires reading one book, that comes with software:

Learning all that is known about the maximum-accuracy paradigm as of the end of 2015 requires reading the following book, currently in production (software not included):

Repeating my comment in another thread, statistics is evolving, and it behooves researchers to read, understand, and evaluate with data the new methods, in order to make an informed decision--whether to cling to the past, or to travel into the future.

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Saving the best (to an angler) for last, I attach another "show-and-tell" photo of a giant in-shore ("skinny water") specimen, a 70 pound cubera (dogtooth snapper), that I caught six years ago by fly-lining a live 10-pound bonito in Pacific waters in Panama (low barometric pressure, strong current, heavy structure, no small forage fish--scattered by an earthquake that occurred two days before this catch). The bait broke for the bottom at breakneck speed, and as soon as it reached "safety" the initial hit and run of the cubera nearly dragged me off of the boat.

Human capital and social capital are two of the five assets that determine the farmers welfare. They influence the capacity of the farmers to develop sustainable practices. At a good level, these capitals help the farmers investing in sustainable farming systems, and then in sustainable fisheries; some fish farming systems that are efficient economically, socially, and environmentally. 

One key determinant of the equilibrium state is a reliable stock-recruit relationship; simply put, when the population of adults is high, the number of fish born that live to be big enough to catch is also high. But this relationship is not often well-understood despite being the basis for most management. And this is but one source of variability.

Fisheries are typically managed in our region by assessing the population size with stock modeling and/or fishery independent indices in relation to thresholds established through historical stock performance or biological limitations. When thresholds are exceeded or approached, the only tactic we use is to reduce fishing effort, including reallocation among user groups. Fortunately, we have an adequate command and control regime so that reductions in effort lead to population growth, although not always does the response happen quickly enough. And we are still vulnerable to the mysteries of recruitment variability! 

Do you mean the honeycomb condition in large frozen fish?

Marine aquatic biota are highly sensitive to pH of water. It is difficult to generalize the impact of ocean acidification as different species have their own range. Apart from reduction in population of native species, introduction of some new species is also possible. In India such a situation was observed in Chilka lake which is fed by sea water.. Change in pH resulted in disappearance of several species.

Hi Marvin, was increase in protein content correlated with decrease in fat content? If yes, it might be related to differences in water temperature due to oceanographic (climate) changes or sample bias. In warmer waters expenses on metabolism are higher so less of fat to deposit.

Thanks Natali. In addition to co-management/ co-governance, i expect to use the traditional top-down, self-governance.

Hi Doug,

a bit late but here are my thoughts, as you say, I guess BMSY management is impossible to be guaranteed even, both under single and multi-species frameworks, simply too many players involved at all ecological levels. But to manage all stocks simultaneously at FMSY should be achieveable, simply to focus on getting the conditions right, the outcome would thus not be dominated by human Impacts (loss of control). Sure, difficult to setting the ranges of stock specific FMSYs right, we just proposed refering  to stainable levels of total including natural mortality rather than fishing mortalities: as a more precautious alternative to cover EFBM:

An alternative reference point in the context of ecosystem-based fisheries management: maximum sustainable dead biomass. Hans-Joachim Rätz, John Casey, Steven J. Holmes, Josep Lloret, Hendrik Dörner, Nikolaos Mitrakis, and Aymen Charef: ICES Journal of Marine Science; doi:10.1093/icesjms/fsv089

Cheers from Hamburg

Hajo

Dear Nagaraj G. Chatakondi and Mohammad A. Momin Siddique ·sir

The number of fertilized eggs are  are sufficient but we found that low survival of hatchlings to fry and fry to fingerlings is due to cannibalism among them. 

We have found that a previously overexploited linefish species, on which a moratorium was placed (F=0) in 1997 appears to have made negligible recovery. We suspect that another species has filled the niche space left behind and is potentially making it difficult for the protected species to bounce back. I mention this because, in our situation it seems that intra-species dynamics are not the only factors making it difficult for the protected species to bounce back. Any amount of fishing effort on this particular stock, which is so degraded, would place undue extra pressure.

Isa, the solution depends on the type of environmental variable or component. For instance , the percentage or proportion of area fished or proportionate cover of seabed habitat,mean trophic index, relative biomass of key target species or keystone prey as indicator of ecological wellbeing are indicators that could be used in respect of trawling. In short, you may refer to a range of ecological indicators which are modified by the commercial trawl fisheries. Visit this website: http://www.fao.org/3/a-am429e.pdf   for  development and use of ecological indicators.

It'd be better if you specified more details on the background of your question.

As far as as I can understand, you need to find out what happens to the marine environment where the bottom (I assume) is trawled. You need to start with description of the bottom character, for each type of bottom would be differently affected. Then comes the description of the fishing gear employed, for each type of trawling gear differently affects the bottom. The first and perhaps the only parameters that can be IMO quantified are the frequency at which each spot of the bottom is passed by a trawl during a given period and, consequently, the spans of time when the bottom can "rest". Next comes the real complexity: the biota in the trawled area, starting with micro-benthos and ending with top predators, especially how the removal of some of it affects the rest. Still another factor, which may affect the environment is the dead and living by-catch jettisoned by the trawlers. I'd say that one must assume a specific qualitative approach to each individual habitat. For some, very non-dynamic habitats where the above factors don't change or their changes can be reliably quantified, a mathematical model may just be valid.    MB-Y

The b factor in the standard allometric equation W=aL^b is really determined empirically by collecting a number of fish either under various conditions you describe or alternatively from pooled data to give an overall average.  Fulton's K on the other hand simply assumes that the weight of the fish is simply proportional to the cube of the length K=100(W/L^3), so in Fulton's equation the b exponent is a constant.   Fulton's CF is often useful if you want to get a "quick and dirty" comparison between fish populations when the empirical study to determine b is not done.  The allometric equation becomes a better measure in flatfish such as flounders and soles in which the b exponent can deviate substantially from the approximate estimate of 3.

Involvement and participation of the concerning institutions (GoB, or GoB Certified authority, NGOs or the institution theta are responsible to set national and international standard) might be a part of the implementation process as well as continuous monitoring/ process (if you want to marketed it to national or global level other than the local compliance). However many country also make these mandatory for local level. So...  You can ask FAO (Agriculture and Fisheries wing) regarding your Query. I think certainly you will be benefited from the support of FAO. 

As was very well described by Dr. Abella, the Mediterranean fisheries are characterised by fragmented fleets, usually composed by small vessels, use of large number of landing sites, multi-species catches and low catches per unit of effort. Most of the fish caught are recruits (0-1 years) of the main target species. Until recently, no regular assessments were made by international working groups and the results of the assessments made rarely were incorporated in management. Moreover there are different fishing methods targeting the same species and remarkable recreational fishing activity (at least 10% of total landings). European statistics indicate there are some 4,300 larger ‘industrial’ or ‘semi-industrial’ units, mainly trawlers and purse seiners, operating from EU ports in the Mediterranean. However, the ‘small scale’ sector, which includes coastal and artisanal fisheries, is especially important. It is estimated that more than 40,000 small scale units are operating from EU ports. This is believed to be less than half of the total number of small vessels fishing in the Mediterranean.

The main problem of the Mediterranean fisheries is overfishing, since the development of semi-industrial and industrial fishery has led to an overexploitation of many fishable resources. Impact of fishing gears to the marine ecosystems (e.g. impact of trawlers on the Posidonia beds) is another important issue, since one of the key principles of ecosystem-based fisheries management is the need to protect ecosystems and populations by applying the precautionary principle, which includes halting destructive fishing methods. In the Mediterranean, catches are falling, the fish caught are getting smaller and some species are becoming rarer. Mediterranean fleets need to fish less and with less environmental impact, improve compliance with the rules, reinforce co-operation between fishermen and scientists and strengthen multilateral co-operation. Thus the return to the alieutic exploitation of the coastal zone through the development of artisanal fishery appears mandatory for Mediterranean fishery. The small-scale fisheries, suitably governed, are still our best hope for sustainable utilisation of coastal resources (Pauly, 2006). However, although small-scale fisheries are potentially, and in many cases actually, more sustainable than large-scale fisheries (they don’t destroy the bottom like the industrial trawlers, they don’t discard, they can target species, etc.), they are disadvantaged because of their typical remoteness, lack of infrastructure, and marginal political power. Furthermore, small-scale fisheries are at a disadvantage when competing for fisheries resources and market access with heavily subsidized industrial fleets.

Mediterranean waters have a very long history of local management from the 3rd millennium BC down through the centuries via the medieval guilds and ‘brotherhoods’ (Prud’homie in France, Confradias in Spain) to modern times. This tradition of local territorially-based management shows that the common pool resources of the seas were benefit of appropriate and effective management. The idea of imposing rights on coastal resources is also emerging as an approach for managing coastal fisheries. The problems of enforcement of regulations in the Mediterranean suggest that management-based incentives, or indirect incentives resulting from systems with increased fishermens’ involvement in the management process, would ultimately be more effective in controlling fishing. Thus the participation of the fishermen in the crucial decision making processes will be the decisive factor for law enforcement and successful management.

The definition of coastal small-scale fisheries is very important when we design management plans for the coastal ecosystems. The coastal fisheries encompass basically the areas which are accessed by the traditional and motorised fishermen who operate their boats which are mostly up to 10 hp and a length of  5-8 m. Thus first and foremost, there should be effective legislation to stop illegal

1)Thus first and foremost, there should be effective legislation to stop illegal in indiscriminate fishing in these regions.

2) Effective and continuous patrolling using patrol boats and coastal police vessels should be implemented

3) Once first two points are done, there should be prohibition to any activities which may change the general biology of fishes (migration, feeding, breeding etc.) like mining, dumping of wastes, etc. 

4) A continuous reporting system  for catch, unique observations (fish death, heavy landing) using ICT and other technological and issues between fishermen should be implemented using the community-based fisheries management

5) If already some systems of fisheries limits exist in the coastal systems (traditional and religious controls), if they found adequate, try to promote them

6) Estimate the fisheries and biodiversity of the ecosystems with rigorous sampling with participatory approach to make the fishermen understand the importance of the study.

7) The projects should be focused for long term to make an impact in the livelihood of fishermen

Stakeholders identification

what whom should  do?

1) Fisheries patrolling- state-level Departments

2) The data collection and analysis from different sources- Research institutions like ICAR

3) Reporting of fisheries data to research institutions and dept.--Fishermen community  on a weekly basis.

4)Awareness and training programmes- Research institutions and Dept.

These come to mind:

1. Legal precedence and cultural attachment to a single-species management structure.  A species not considered overfished in a single-species context may be overfished in an ecosystem context. 

2.  A focus on only  growth and recruitment overfishing in fishery management.  

3.  The fixation by fisheries management to only allocate resources only for fishery extraction.  No allocations are provided for non-extractive uses such as recreational diving, tourism, education, science, or conservation.  The "right to fish" is widely discussed but not "rights to have undisturbed areas with public access " for nature appreciation, education, science, or conservation.  While many areas that prohibit hunting exist on land and are widely accepted, analogous aquatic areas that prohibit fishing are rare.   

4. A over reliance on stock wide assessment models and the lack of spatially explicit, stock assessment models.

5. Lack of accepted ecosystem models that can integrate climate, productivity, oceanography, and trophic and fishery interactions.

6.  A failure to incorporate a precautionary principle into management.  Because we have imperfect knowledge, some areas should be set aside with minimum disturbance.  

7. A preoccupation with short term economic impacts versus a long-term ecosystem persistence.   Although economic considerations are important, they are not sufficient.   Economics must be balanced with ethics.  Self-interest must also involve obligations, responsibility, and self-sacrifice.  

8. More proximate and pragmatic problems are misinformation, ignorance, stupidity, stubbornness, greed, and arrogance.

Dear Hugo,

I copy here some works:

Batsleer, J., Poos, J., Marchal, P., Vermard, Y., & Rijnsdorp, A. (2013). Mixed fisheries management: protecting the weakest link. Marine Ecology Progress Series, 479, 177–190. doi: 10.3354/ meps 10203

Feekings, J., Bartolino, V., Madsen, N., & Catchpole, T. (2012). Fishery discards: Factors affecting their variability within a demersal trawl fishery. PLos One, 7(4). doi: 10.1371/ journal.pone.0036409

Sardà, F., Coll, M., Heymans, J. J., and Stergiou, K. 2013. Overlooked impacts and challenges of the new European discard ban. Fish & Fisheries.

I hope they would be helpful for you.

Shahram

Luis,

Much depends on what you mean by "successful" and come to that what you mean by "management". If you are looking for examples of success of "modern" (i.e. government-centred, science-based, conservation-oriented) fisheries management, you will have to search long and hard, whether you include all fisheries or just the small-scale ones.

On the other hand, human beings managed their fishing, more or less successfully, for millennia before the advent of large-scale, offshore fishing -- during an era when data (in the modern sense) did not exist at all. Ever-evolving variants of the systems used in the distant past have continued to be employed, still with some success, down to the present time, though they are being gradually swept aside by governmental imposition of the "modern" form of management (designed to address the problems of the large-scale, offshore fisheries -- though conspicuously ineffective for that purpose).

The best introduction to the topic is probably the ethnographic literature on the Polynesian, Micronesian and Melanesian peoples. There is also a substantial literature on the lobster fisheries of Maine, which provides insight into an application in a modern, highly-developed nation. Beyond those, you can just delve into the fisheries social-anthropology literature. Not all is directly relevant to the management of fishing but community-based management must be founded in communities and hence their structure must underpin the success (or failure) of that management.

Trevor Kenchington

This is a very interesting question. It seems to me it would be very valuable to know the percent of eggs harvested. Another approach may be to estimate the the coverage of floating algae, which could potentially be done using the Floating Algae Index (FAI) which can be obtained using satellite data. There would need to be a lot of assumptions made, but you could possibly obtain a rough estimate of "fishing" egg mortality by comparing the areal coverage of floating algae to the coverage of fishing mats. This might give you another approach to estimating of spawning biomass as well. Then using additional estimates of juvenile mortality (with the species I worked with there aren't truly flying fish larvae as they are born with the full compliment of fin rays) and adult mortality you may be able to improve your model. I have some "larval" daily growth data for a Gulf of Mexico species (using otolith increment analysis) which I doubt will have any practical use, but if you want to look at it as sample data, I could provide it for you. I also have some flying fish references that may be useful.

Globally, bait species used in longline fisheries are highly variable depending on fleet, species targeted, local bait availability, imported bait availability and prices. I would suggest to you either to develop a deep bibliographic survey in longline fisheries publications or to distribute a specific questionnaire, than to pose such question on Research Gate. Responses you’ll get from a couple of scientists based on limited local knowledge may heavily deviate from global average. In general tuna fishing fleet use small pelagics as bait; such as: Cololabis saira, Scomber scombrus, Scomber japonicus, Sardina pilchardus, several species of Decapterus and Trachurus. Pacific fleets widely use locally produced milkfish Chanos chanos. Swordfish targeting fleets usually use squid bait, however many tuna fleets use squids as secondary or primary bait also. Squids for bait mostly originate from jig fisheries, usually from Southwestern Atlantic: Illex argentinus. However trawl-caught species like Nototodarus spp from New Zealand also used despite lower quality of trawl-caught squids. Other Illex species or mass species like Todarodes pacificus often used locally or internationally. Finally some swordfish targeting fleets use fish bait Scomber spp also. This is complex question, therefore and detailed study of fleets and markets is probably necessary. In addition I am not talking about demersal longline fisheries that also widespread around the World and use variety of species for bait. Hope this helps.

In some countries, fishermen are shy to provide truthfully their catch data because they may be used by their authorities for taxation purpose, such as income tax, or by monopolistic fish-buyers to whom the fishermen are obliged to deliver all their fish. In such cases, the best way is to create a system, by which such data are supplied to fishery statisticians anonymously.

Try this paper "Gaining Perspective on What We've Lost: The Reliability of Encoded Anecdotes in Historical Ecology"

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0043386. Also paper attached. It suggest an innovative way to bring back data from the past...

"Are Huso huso, Acipenser stellatus and Acipenser gueldenstaedtii legally protected in Serbia, Romania or Bulgaria?"

In Romania: Huso huso and Acipenser stellatus since 1993 (details in Annex III of Act 13/1993).

The others few years later.

SST functions for only 2 to 3 days after the data is downloaded,beyond which it is ineffective.Certain maritime states have their own fishing rules in order to have sustainability.For e.g.Kerala doesn't allow mechanized vessels to operate within 5 KMs coastal zone.Other states do have closed fishing seasons, coinciding with fish breeding season. But the point here is the authorities can't effectively monitor any part of fishing activity,thereby leaving the area to be free for all.To compound the problem,foreign vessels say from Taiwan do fish in potential zones & get scot free - due to laxity in monitoring.Moreover in the name of catching fish wherein fish trawl is to be used,almost all the trawlers use shrimp trawl,smothering the benthic structure of sea beds.The cod end mesh size is so small that even baby fishes get caught to the extent of 80% of the total catch of the trawlers.This waste doesn't even fetch any price & being a waste,directly hits future stock.The fishermen are so cleaver that they know each of the potential fishing zones among them selves & they don't depend on any advices from authorities.