Our scientific programme on bass and other fish: a personal perspective by Michel Kaiser

What is my interest in fisheries?
When I was 14 I used to correspond with Mike Ladle, who many veteran bass anglers may remember as a regular columnist in Sea Angler magazine. Mike was the champion of plugging back in the days when most people were fixated on live or 'real' baits. I wrote to Mike to seek his advice about a career in marine biology. To my shock he wrote back and we corresponded for a number of years but sadly, we never met. Well his advice must have been good because I've been doing research on commercial and recreational fisheries for over 20 years, working for both CEFAS (from 1991-1998) and Bangor University where I head up a large team focused on issues around sustainable fisheries.

What is the use of science?
Fisheries science is all about understanding how populations respond to harvesting, hence if a fish stock is healthy, then it is conserved. In our approach to fisheries management we also have to understand how fisheries impact other parts of the ecosystem such as the fishes' habitat. We have a long track record in understanding how fishing affects seabed habitats and this has led to significant changes in policies around the UK. This approach fits very well with the 'Striking the Balance' document produced by the Welsh Fishermen's Association.

The other key aspect of fisheries science is that we deal with "evidence". Indeed controversies abound due to a poor or distorted use of evidence or the portrayal of opinion as fact. Once a scientist steps over this line then he/she has undermined their credibility.

Although much of our research is focused on commercial fisheries, we have published a number of science studies using sea angling data, two stand out. Back in 2006 we published some work on the community supported Inshore Potting Agreement in Start Bay, Devon. This is a gear restriction management area that means that only static gear and angling are allowed in certain areas of the sea, while other areas rotate between static and towed fishing gears. Our research showed that individual specimens of some species of fish reported by anglers were much larger in the vicinity of this area than other outlying areas. However not all species were conferred protection, thus while spotted ray and dab got bigger, blonde rays did not.

In the same year as the Start Bay work, we published another study showing how angling data provides a powerful indicator of fish stock health that tracked fisheries surveys. This study shows the really useful potential of using angling data to inform fisheries science on stock status.

What are we doing in Wales?
At present we are involved in a project that seeks to provide the science to underpin sustainable marine fisheries in Wales. To date Wales has been overlooked in comparison to other UK areas and the science has been ad hoc at best. Our challenge is to put in place scientific monitoring, in close cooperation with fishers, to give the Welsh Government much better insights into the state of the stocks in Wales and how best to manage them.

One of the species highlighted for action is bass. Bass are important both to recreational anglers and commercial fishers, however a paucity of information collected on a regular basis has undoubtedly led to recreational and commercial fishing being undervalued in Wales. Understanding the value of fishing is important when Government make choices about investment into services that might enhance the fishing experience and profitability (e.g. better launch facilities, surveillance of illegal fishing in all sectors etc). To that end we are undertaking an economic survey of all areas of fishing in Wales to understand much more precisely how sea fishing in all its forms contributes to the wider economy.

At present our main focus is on bass but we will include other species such as rays and other elasmobranchs (e.g. tope and smoothhounds) later in the project.

How does better information in Wales affect the European dimension?
With devolution comes the responsibility to manage the fish stocks in your own waters, it also gives the Welsh Government a voice at an international level regarding activities that might impact fish in home waters.

We know at present that the vast majority of bass spawn in the English Channel where the French account for 80% of commercial landings from commercial fishing vessels. There are probably other spawning areas and identifying those is a priority for us. If we can find local spawning aggregations we may have locally adapted fish that could be considered a local stock and hence managed at that level.

Understanding the contribution of the English Channel bass to the bass we see in Wales is important because the Welsh Government can make a case for the needs of Welsh recreational and commercial fisheries to be taken into account in any negotiations about potential management. However without the scientific evidence none of this is possible. To identify these spawning areas we need to collect guts with the sex organs of fish to ascertain their maturity stage (e.g. ripe) and genetic samples (fin clips) to understand population structure across Europe (this is through a large EU funded project).

What are we trying to achieve?
We need to know how much is caught in which area and by whom (e.g. recreational or commercial sector). Second we need to understand population structure (the number of older and younger fish, and their size) which will give some insights into population health. To do this we are collecting scales from fish across Wales and from fish processors.

ICES attempted the first stock assessment of bass this year but failed due to uncertainties in the data, however all the indicators suggest that the spawning stock biomass is on a steeply declining trajectory. This is not surprising given there are no controls on the amount of bass currently caught as this is a non-quota species.

We also want to understand the recruitment of bass into nursery areas (e.g. estuaries) and set up a long term monitoring programme that will provide a recruitment index and an insight into future populations. The last few years have seen poor recruitment in Welsh waters based on our conversations with the NRW (former EA in Wales), and this year seems to be following that pattern based on a recent survey we undertook in estuaries around Wales.

Who are we working with?
We are working with all and any fishermen that will participate in our study, we have asked various organisations (like WFA, BASS and the WFSA) to publicise what we are doing to extend our outreach, but the project is entirely independent reporting to a stakeholder panel made up of angling representation, commercial fishers, and Government bodies.

What do we do with data from individual fishers?
Information provided to us is treated with the highest level of confidentiality, indeed we have gone to great lengths to protect all fishermen from malicious freedom of information requests.

We are interested in general population trends and not "where is the best place to catch 10 lb bass?". If we show data in a mapped form it will be aggregated to large scales, demarcated by biological boundaries imposed by the environment (e.g. seawater temperature). Thus we might show graphs that display the age distribution of all fish caught from for example, the LLŷn Peninsula. What we won't show are all the bass caught by Mike Kaiser in 2013 at Menai Bridge...which would be a big fat zero so far!

We will report aggregated commercial and recreational data separately, but that is because we might expect there to be a big difference in the age groups targeted by these two groups and this may have important implications for understanding which fish are vulnerable to different types of fishing at different stages of their life history.

Why work with us?
This is your opportunity to contribute knowledge where currently there is a major gap. And why should you care about this gap? Without a better understanding of the status of bass and other fish like rays in Welsh waters it will be impossible for the Welsh Government to engage in helping all sectors of the fishing community improve the sustainability of fishing into the future.

In the past a lack of data tended to work in the fisherman's favour, but these days there is a growing need to provide evidence of the impact of our activities on the marine environment to be able to continue pursuing our hobby or livelihood, for which we need your help.

Questions and Answers

The following questions have been collated in response to 3 threads posted on WSF as follows:

In addition we requested that anglers post any further questions we had missed. All comments made were taken on board and lead to the finalised list which appears with responses below.

Please note, any opinions implicit in the questions exist to illustrative the query. They do not reflect any view held by Bangor University Fisheries and Conservation Team members.


Who is funding and partnering with Bangor University Fisheries and Conservation Team (BUFCT) on this project?
The project "Sustainable Use of Fisheries Resources in Welsh Waters" will deliver science that will support the objectives of the Welsh Government's "Wales Fisheries Strategy" (WFS) and the vision proposed by industry in "Striking the balance". The project is overseen by a panel that comprises commercial and recreational fishing interests and the project is funded through the European Commission's European Fisheries Fund. All reports and financial claims are posted on the group website

What are the aims of the project and the objectives of the recreational sea angling (RSA) Sea bass study in particular?
To paraphrase Michel, the project seeks to provide the science to underpin sustainable marine fisheries in Wales, objectives are summarised under "What are we trying to achieve?". To add a detailed objective of particular interest to me, we are investigating if recreational bass catches recorded in diaries and match cards could be used as a barometer of bass stock health.

We are also evaluating the use of software in angler's catch diary recording and are collecting opinions via an online survey. To be useful, this will apply to all fish species and not be restricted to bass.

I have heard requests for several types of data, for example collection of biological samples, my diary data and economic data, can you clarify what you're collecting from anglers?
The samples of scales, guts, gonads and fin clips (i.e. biological samples) we collect will be analysed to understand population structure. Looking at fin DNA may show how closely related bass taken from different regions are (see "How does better information in Wales affect the European dimension?" and "What are we trying to achieve?"). We are grateful for biological samples from all sources, though we have primarily targeted those handling more fish (i.e. commercial entities) to get the most bang for our buck!

In addition to the biological sample work, efforts are being made to get catch diary and match cards, to see how well bass are represented in these sources, and where there are bass, to collate the bass information for further analysis (see "Specifically, how will my historical catch data and biological samples be used, by whom and who will see the final reports?")

Efforts on catch diary and match cards have been targeted predominantly at angling clubs and charter boat skippers because they are easier to contact (in theory!), they may have more data in one place and their angling sessions are expected to have less historical variation for some factors (e.g. where fished and when fished).

We are currently engaged in economic surveys aimed at the commercial sector, these will ask multiple questions to provide estimates of the economic contribution of fishers to the welsh economy and will allow comparison with previous economic assessments. It is likely that a recreational economic assessment will follow, however we are just evaluating if projections from previous studies will suffice.

There have been other studies into RSA, why should I participate in this one in particular?
This study is expected to be a significant influence on the Welsh Government's "Wales Fisheries Strategy", which makes it influential, regionally specific, and timely in view of the increased interest in European bass fisheries. This is a strategy which includes the quote "the Strategy is ... set against the backdrop of improving ... angling, not least as a healthy past time which encourages people to get outdoors".

What involvement do BASS and WFSA have with the project?
WFSA and BASS do not fund any aspect of the project. They have not requested the compilation of reports or any other outputs on their behalf as a result of their cooperation or otherwise. They will only have access to outputs which will be published in the public domain. Both BASS and WFSA actively support the study by engaging with their members and with the wider angling community for which I make no bones about being very grateful.

What will be the likely outcome if anglers do not cooperate in this study?
Having an incomplete assessment of the Welsh bass stock will weaken the Welsh government's position in any fisheries management negotiations. Additionally, if the extent and importance of the commercial and recreational sectors are underrepresented because of a failure to engage, then it is difficult to make a case to channel investment into improvements to support the fishery and related services.

Data Handling

Specifically, how will you ensure that my fishing locations are protected?
Both the biological sample data and the catch diary data only require the location at a resolution you are happy to provide, for example, "Holy Island" (low resolution) rather than "The Lily Ponds", or GPS coordinates (high resolution).

GPS trackers are optional, and have been provided for the biological sampling, primarily to the commercial boat fishers who have elected to use them. High resolution location data is preferable and the electronic collection of GPS data significantly decreases our data handling effort. GPS is particularly relevant to boat fishers who may travel miles offshore, crossing the environmental gradients Michel previously mentioned. However, it certainly is not compulsory to use a GPS tracker or record your GPS coordinates.

When providing data, there is an informed consent document which gives guarantees that only the Bangor University team (BU) will have access to your submitted data for as long as that data exists and that any reports released outside of the BU team will summarise and anonymise data to a low resolution, making it impossible to identify specific locations or an individual's contribution.

What measures are taken to protect my data while under BUFCT custody?
Data is retained on the University's secured network in a location dedicated to the project, protected under Windows Active Directory file system security. Only authorised Bangor University project team members have read access to this network location.

What will happen with my data after the Sustainable Fisheries project closes?
Data will be retained for 5 years after project completion, after which point any personal details will be destroyed. It will remain under the custody of BU until destroyed.

If I change my mind, deciding not to cooperate, will you delete my data held under your custody?
Yes, your data will be removed on request.

Specifically, how will my historical catch data and biological samples be used, by whom and who will be able to see the final reports?
The collection of anglers' bass catch data (diary and match cards) is being trialled to see if it could be a useful indicator of stock health. We are also looking into the feasibility of an online web diary for anglers and charter boat skippers. Your diary data and the response to requests for diaries will help determine what the application needs to do and whether it could receive enough support to be viable.

Biological samples from measured fish will be used by the BU team to calculate key numbers used in population dynamics. An example is male and female age at maturity, which ages the fish from the scales and measures the sex and maturity from the gonads. Genetic analysis will help determine how closely related fish are across regions which is very important for stock management. Also see Michel's "How does better information in Wales affect the European dimension?"

The data you directly submit is protected by an informed consent agreement and only BU team members will have access. The team will combine your anonymised data with that of other participants and then analyse it. The primary consumer of the analysis results will be the Welsh Government, but as a project effectively funded with public money, the results and the methods by which the results were arrived at, will be in the public domain.

Who will have access to my data
Your data, (encompassing your catch records from diaries and match cards; and any data accompanying your biological samples, and any survey responses which include your name or other information which allows you to be personally identified) will only be accessible by the BU team.

Fisheries Science

The BUFCT literature claims "Fewer and smaller bass are being caught by anglers in Wales", what evidence supports this?
This is derived primarily from a survey in 2004 by Dr E. A. Richardson in which charter boat skippers reported fewer and smaller bass, and commercial anglers reported smaller bass. Anecdotal comments from anglers during fishing surveys also indicate a decrease in the size and abundance of fish in general (not strong evidence). Our intentions were honourable, but we accept the source should have been made clearer, however space on the leaflet was limited.

Will the findings of this study lead to the implementation of harvest control rules (HCR) for RSAs, exampled by changes in MLS, bag limits and no take zones?
The study seeks to improve the understanding of the Welsh bass population and the pressure to which it is subjected across all fishery sectors. The recreational work at this stage is about understanding bass targeted angling; the extent and value of historical data, and how best to direct future effort to accurately assess the recreational fishery.

Hence harvest control rules will not be implemented as a result of providing us with your bass catch diaries and match cards or cooperation with our current surveys.

It is also important say that any fisheries management decisions will be taken by the Welsh Government and the European Commission. The drafting and application of any HCR's is not dependant on scientific evidence in isolation; economic, social, political and historic factors all play a part.

Many anglers have reported decreases/increases in catch numbers and fish size, why is this body of evidence insufficient to inform fisheries policy?
Unfortunately anecdotal evidence is notoriously unreliable and is only qualitative and so cannot be used directly in fisheries management or in rigorous statistical tests. Anecdotal evidence from experienced sources is valued and is often the starting point of scientific investigation.

Why is the project studying Sea bass when the stocks of Cod, Angel Shark, skates and rays, and Spurdog are in a much worse state?
Bass are of particular interest because they are a non quota species, are of particular value to anglers who in surveys cite them as the fish they most target, are an important commercial species to the welsh inshore fishery, and there is increasing pressure across the EU for member states to report on bass as it is a data poor species, under increasing exploitation.

Takes of Sea bass from recreational angling are insignificant in comparison to the commercial catches which exploit spawning aggregations in the English Channel, so why assess it?
To reiterate, the recreational work at this stage is about understanding bass targeted angling; the extent and value of historical data, and how best to direct future effort to accurately assess the recreational fishery.

As a general principle though, the assertion that angling take is insignificant needs to be assessed as it cannot just be taken as fact without proper evidence. That there is some recreational catch is beyond doubt and so estimating that catch is important in assessing stock health. It is a piece of the jigsaw, ultimately we need to know the size and shape of that piece before we can add it in to help complete (an approximation) of the picture.

Commercial fishing already provides reliable data which can be used to study population dynamics to inform policy, so why collect our data?
There are many problems associated with solely relying on commercial landings (fisheries dependent data to use the correct term) for stock assessment, however the most obvious problem for us is that it does not provide details about age, sex, maturity, length and genetic differences.

Sea bass population dynamics are affected by environmental factors, for example short and long term sea temperature changes. How can I be sure that scientists will correctly interpret my catch data and will these factors be investigated?
The possible influence of these factors are certainly accepted, statistical techniques can be used to determine which factors may be associated with biological and abundance changes in bass and ocean temperature is certainly of interest.

Scientists will rarely reach conclusions outside those which the study has set out to measure or test, and recognising study limitations is critical. This is also why it is important that reports or papers include or reference the methods used to derive the results and conclusions so limitations and errors can be spotted during peer review.

Sea bass are migratory, what use is there in a study restricted to Welsh waters?
Though bass are migratory, there is some evidence for a separate stock in the Irish Sea and it is hoped our biological sample work will help to answer the important question of stock structure. Michel also addresses this in "How does better information in Wales affect the European dimension?".

Bass also tend to return to the area they matured in, so adult bass caught in Welsh waters will generally return to the same region year on year (this region can be quite small). It is important to study this "philopatry" as it may prove useful in understanding the effects of sea temperature change, which requires a lot of information with the location, seperated by time.

Why shouldn't I submit massaged catch data to favourably influence the study results
This project concerns sustainable fisheries; no one has a long term advantage in underestimating or overestimating catches. In addition, data will be analysed statistically to see if it is unusually different from other data, this is an essential part of any scientific data processing. Finally, it would be hard to predict the outcome of under or over estimating catches or sizes, certainly the picture is not straight forward and it is better to make your individual case from a position supported by data you know is accurate.

Netting of Sea bass is very common, what is the team doing to assess this?
The project aims to assess hobby netting and we are developing a strategy on how this is best achieved. Netters targeting bass are more than welcome to participate in the study as outlined, including contributing diary and bass biological samples and are welcome to contact the BU team.

As scientists how do you maintain objectivity?
Please see Michel's "What is the use of science?".

Give yourself a cookie if you got this far, I have!

I will do my best to respond to any questions, though there may be times when I have to refer to my collegues, as I want to ensure they are as accurately answered as possible.

Finally, I'd like to add that I do use this forum as an angler, not just a scientist - my posts by default are as an angler and are not the opinions of the Fisheries Team unless specified.

The responses above have been reviewed and agreed by Michel.