A10. Angler Citizen Science

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Figure 1: An excerpt from the annual Salmonid and Freshwater Fisheries Statistics report for England and Wales 2020.

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1. Purpose

Angler catch return schemes and citizen science initiatives are an important tool for fisheries managers by:

  • Providing information on the relative abundance of key fish species and life stages
  • Providing information on the indicative and relative abundance of key fish species and lifestages in a river reach
  • Detecting perturbations in river quality if other monitoring activities (e.g. microinvertebrate monitoring) are used

Angler citizen science is an important tool for fisheries managers and to understand as it offers some fundamental advantages over many other sampling techniques, whether it is to monitor the positive influences of improved habitats or conversely to highlight declines in species and their respective habitats.

Monitoring of catches of fish taken by angling (rod-and-line) can provide information on the indicative and relative abundance of key fish species and lifestages in a river reach. It generally will not provide information on early lifestages – larvae and fry – or on species not normally caught or targeted by anglers, for instance the very small species such as stickleback, stoneloach and bullhead.

2. Method Summary

Figure 2. Individual angler – census record card

There are a number of possibilities for collection of angling catch data depending on species of interest and location. In England and Wales, rod licence holders are required by law to report catches of adult migratory salmonids – salmon and sea trout - to the Environment Agency/Natural Resources Wales and these data have been collected over many decades and summary data are publicly available (example shown in figure 1).

Rod catch data such as these must be viewed in the context of fishing effort (measured as rod-days) and anglers are also required to record number of days fished as well as time and place of capture of individual fish. In addition to these data, individual river fishery owners and lessees usually maintain their own records and in other countries these may be the primary source of catch data. No formal reporting of catches of non-migratory trout and coarse fish is legally required in England and Wales, hence in order to monitor changes in fish communities in relation river restoration, special programmes will usually be required.

2.1 Direct assessment

Monitoring the size and composition of individual angler’s catches by a qualified, paid person who walks the river bank whilst anglers are fishing. This approach is particularly suited to smaller rivers where angling takes place informally, but has been used on much larger fisheries for example in the United States State Fish and Wildlife Service staff will interview anglers on the bank and gather catch data and record angling trends.

2.2 Use of third parties

Figure 3. An example of a match catch return form submitted to the Environment Agency.

Probably the most common method of obtaining data, from individual recreational anglers using log books and other catch return stationary, or from angling competition returns completed by match organisers, which can be collated and analysed by the Environment Agency (in England).

There is a limit to the level of detail typically included in third party data and for the Agency’s match catch system this includes:

  • The number of competitors partaking
  • The number of successful anglers weighing-in (those who returned a small catch of fish and left the riverbank before the end of the timed competition are not recorded).
  • The top three weights are recorded individually.
  • The total weight brought to the weighing scales by successful anglers.
  • The species in greatest number.
  • The second greatest number are recorded.
  • Other species caught.
  • River and Weather Conditions

In the example in Figure 3, the match card is a return from Ripon Piscatorial Association on the River Ure around Ripon, North Yorkshire, from a match on the 20th February 2005. Only 21 of the 65 anglers weighed in, the winning weight was 52lb 5oz. The total weight brought to the scales was 335lb 3oz, this was made up of mainly chub, followed by grayling and trout.

The river was low and clear, when the match started the weather was very cold with snow showers, before giving way to bright sunshine. Individual angler log-book schemes such as might be operated by fishery owners or small game angling clubs may contain more detail especially on the sizes of individual fish.

2.3 Information in the public domain

Figure 4. Examples of angling match catch data from press and online sources.

Information such as the weekly angling press is now extremely limited, this has been quickly replaced by anglers and organiser sharing catch reports and the results of competitions online, this is more applicable to larger, more popular fisheries. These kinds of data are more difficult to interpret as the reporting format varies hugely but in many cases may be the only data source especially for earlier decades. Examples of press and online reports are shown in figure 4.

2.4 Example

An example of how angling catch data have been used to assess impacts of river engineering is show in figure 5 below.

In 1974 the water authority built a barrage at the confluence of the Yorkshire Ouse at Barmby. The barrage stopped the ingress of heavily turbid waters allowing drinking water to be easily abstracted at nearby Loftsome water treatment works. The barrage had no fish pass provisions and as a result the catches of catadromous species - flounder and later eel - plummeted.

3. Advantages

Figure 5. Catches of bleak, eel and flounder in fishing matches on the lower Yorkshire Derwent, 1971 - 2003.
  • The fish are already captured by anglers, obviating the need to deploy other sampling methods which are generally costly, manpower-intensive and often invasive, and impractical for some fish species in some river types.
  • Other fish sampling methods such as electric fishing and seine-netting only provide a ‘snap-shot’ of that fishery on the day of sampling, in most cases at limited, pre-defined sites. Recreational angling on long reaches of river can be monitored over a whole season, meaning that overall results are less influenced by short-term spatio-temporal changes in fish distribution or by differences in individual angler skill or changing weather conditions. In addition, seasonal changes in fish distribution may also be monitored.
  • Angling has been a popular activity for centuries, some fisheries such as the famed Scottish salmon rivers have many years of data relating to the numbers and sizes of salmon and grilse caught each season dating as far back as the 1700’s; coarse fish match catch records may date as far back as the mid – 20th century in some cases, comfortably pre-dating modern fish sampling by UK agencies, thus enabling much longer-term views of fish population abundance and community structure.
  • Collecting angler catch data provides an excellent opportunity to assess the recreational performance of a fishery and its socio-economics
  • Using angler catch data can sometimes help fishery managers and administrators to communicate key messages to the angling community more effectively than simply quoting fish abundance data or ecological indices.

4. Disadvantages

  • This data is only worthwhile if we obtain enough information from the anglers. The detailed accounts of infrequent angling trips by just a handful of anglers provide very little context.
  • Can be very selective – researchers need to be aware of the scope of the angling methods being used and the format of the fishing itself.

For instance records from game anglers using fly fishing and spinning methods will exclude most other species, whilst in most coarse fishing matches, only certain species are allowed to be weighed and pike, zander, salmonids and eels are excluded from some events and are therefore not recorded. Some competitions only allow fish of over a certain size to be weighed hence in such cases small / young fish will not be recorded or even caught in the first place.

Fishery researchers need to appreciate anglers’ behaviours and choices, particularly when using data from angling competitions. One off competitions fished by individual anglers aiming to win large money prizes will just target the species and size class of fish that will allow them to amass a large total weight capable of winning a prize. Such events give skewed representation of the fishery as smaller more prolific species such as bleak (Alburnus alburnus) and Gudgeon (Gobio gobio) may be ignored. Anglers who feel that they have caught insufficient fish to win them a prize are likely to quit the event in the later stages and not record their catch. The data from such events can therefore give the false impression that there is a shortage of fish.

Conversely an angling competition on the same stretch of river fished as a league and/or team event will see angler ‘weigh-in’ even the smallest of catches to avoid a ‘blank’ and penalty points, these may provide a better yardstick of the true status of the fishery

  • Inability by some anglers to correctly identify species caught or make correct recollections of what they have caught. For instance, small chub (Squalius cephalus) and dace (Leuciscus leuciscus) are often confused, as are small bronze bream Abramis brama and silver bream (Blicca bjoerkna).
  • Angling census clerks have found that some anglers exaggerated the number and/or size of fish they had caught when compared with visual inspection of catches temporarily retained in keepnets
  • Under-reporting due to poor angler cooperation. It can often be difficult to maintain good relationships with angling groups as personnel in both the groups themselves and the fisheries agencies change through time; catch return systems run largely on goodwill or minimal incentivization. Even statutory reporting schemes such as the EA’s migratory salmonid catch return system suffer from under-reporting.

5. Cost

Collection of angler-catch data can be very cheap related to more formal methods of fishery assessment, especially if on-line reporting systems can be adopted. However they do not come free: one should not underestimate the time and effort required to build and maintain relationships with anglers and to constantly feed back the results from the monitoring – people tend to lose interest if they don’t see results or fail to understand how they are being used.

6. Data analysis

Key points to bear in mind when analysing angler catch data are that the data are typically very “noisy” and are usually only worthwhile if they can be gathered in quantity over a number of years. Researchers need to consider all parameters for which data are available, for instance whilst mean catch per unit effort will typically be a key metric, they should also consider the maximum catch, ranked catches, number of anglers without catch, as well as environmental variables such as temperature, flow, time of day fished, duration of fishing, species and sizes of fish caught. In the context of river restoration these need to take account of the hypothesis being tested, for instance that and improvement in tree cover and instream habitat will increase carrying capacity for large chub or trout.

7. Summary

Collecting and collating both old and new angler catch data, is an excellent tool for gaining an insight into the performance of our recreational fisheries whether they be small headwater streams fished by discerning wild trout fly fishing enthusiast or large lowland rivers frequented by coarse match angler. Plenty of data have to be continuously collected so the data is robust enough and anomalies like the mis-identification of species or particularly poor days of angling have less bearing on the overall analysis.

The UK is a long way behind other countries such as the USA when it comes to this type of monitoring. We currently only have a few worthwhile data sets, unfortunately many schemes have been disbanded, in many cases due to weakening relationships between fishery administrators and figureheads in the local angling community.

The angling community continue to report angling data and there is great enthusiasm within their ranks to do so. However, river managers and anglers need to work together to ensure that this is maintained and that the data can be collected and collated in a form that optimises their usefulness.