Fisheries Management Measures within Scottish Offshore Marine Protected Areas (MPAs) - Socio-Economic Impact Assessment

9. Limitations and Uncertainties

Overview

All of the estimates of costs and benefits are subject to significant uncertainties. Limitations and uncertainties in relation to the impact on fishing activity, social impacts, public sector costs and environmental impacts are described below.

Fishing Activity

VMS pings occur at least every two hours, and therefore do not provide a complete picture of fishing activity. However, by using data over a five-year period this limitation is minimised. The process of averaging daily logbook landings data across VMS positions at fishing speed may result in landings values being over- or under-estimated for individual pings. The classification of gear types relies on the information reported in logbooks. Some gears may be wrongly classified.

The extent to which displacement of fishing activity will occur (rather than loss of the value of landings), and the nature of displacement (areas or gear types to which effort might be displaced) is uncertain. The knock-on impacts in terms of environmental impacts, impacts on vessels affected and impacts on other vessels, are also uncertain. For those gears that did not pass the displacement test, it was assumed that the value of landings would be lost. However, in practice it is likely that at least part of the effort would be displaced, and this could result in additional environmental impacts, impacts on the vessels displaced, and on other vessels. Conversely, for the higher end of the range for the estimates of Option and Option 2, it is assumed that all of the value of landings affected would be lost, but in reality a level of displacement of activity is likely to occur.

As the value of future landings cannot be forecast, it is assumed that the value of landings are constant over time. The average value of landings per year estimated for each site is therefore assumed to be the same in each of the 20 years covered by the quantification of impacts. In reality, it is likely that the value of landings in each site would fluctuate over time, depending on regulations, quotas, markets and environmental influences, and hence the estimated loss in landings may underestimate or overestimate the true future value of landings. As the GVA and employment estimates are based on the value of affected landings the same limitation applies.

Fishing patterns may have changed compared to the period from which data were used for the assessment (2015–2019). This means that where fishing effort has been displaced from other areas (e.g. due to other management measures, offshore wind farms, or other developments), this may not be fully captured in the data used for the assessment. The introduction of the Deep Sea Regulations in 2016 mean that mobile demersal activity is already prohibited in waters deeper than 800 m. Inclusion of activity data from 2015 in the assessments mean that the impact on fishing may be overestimated in some cases.

Impacts on employment and on the downstream processing sector are considered in relation to the registered home port district and the landings port, respectively, of the affected vessels. In cases where vessels do not operate from their registered home port, this may result in an incorrect attribution of employment impacts geographically. In cases where landings are processed in areas other than close to the port of landing, this may result in an incorrect attribution of impacts on the downstream supply chain.

Gear type information on non-UK vessels is uncertain, and has been assessed based on available information but is not trip-specific. Impacts on non-UK vessels have not been able to be quantified in monetary terms but are assessed in terms of number of vessels by nationality and time fishing. Similar caveats on identifying fishing activity from VMS pings apply as with UK vessels.

The multipliers used to estimate the indirect GVA impacts and the direct plus indirect employment effect, that could be generated from the estimated reduction in the value of landings, relate to ‘Marine Fishing and Freshwater Fishing’ and not the specific gear types affected. They may, therefore, underestimate or overestimate the impacts. The multipliers – which are national multipliers – have been applied at the site level and regional/port level to estimate the economic impacts by site and by region/port. Local and regional multipliers are not available and hence the application of national multipliers may overestimate or underestimate the size and geographical distribution of impacts. Finally, application of the multipliers also assumes that a reduction in output is similar to a change in final demand and that there is no rise in the price of fish to offset the reductions in the value of landings.

The potential costs to the industry of a possible increase in VMS polling rates is uncertain; currently this has been attributed to public sector costs, but there may be cost impacts for the industry depending on the means of implementation.

Within this study, cumulative and in-combination effects have been assessed as the sum of the individual impacts across the sites and in combination with other marine developments. If restriction of fishing activity results in some fishing businesses ceasing activity completely, the overall impacts could be greater.

Social Impacts

The main potential social impacts identified within the assessment relate to impacts on the commercial fishing sector. Given the range of the economic impacts on commercial fishing identified across the options analysed, the social consequences of the proposed management options are also similarly uncertain.

The worst-case impacts identified under Option 2 are relatively small for the majority of sites. While there are uncertainties in the exact extent of these impacts, there is reasonable confidence in the general conclusion that they are unlikely to be economically or socially significant at a Scottish level. However, the cumulative worst-case impacts from a small number of sites could have adverse social impacts in specific coastal communities.

Public Sector

Costs on the public sector are uncertain and may be higher or lower than estimated. The scope, scale and frequency of monitoring requirements may significantly affect the estimates of public sector costs for monitoring. The costs include additional regulatory and advisory costs associated with licensing decisions are dependent on the number of licence applications that are brought forward, and this is subject to the same uncertainties as the cost impacts on relevant marine activities.

Environmental Impacts

In general, there is moderate uncertainty on the extent of ecosystem service impacts, although this varies across services. The management options would provide significant protection to a wide range of seabed features, and therefore protect and enhance their role in food webs. This could result in improved ecosystem health, and provide benefits by supporting commercial fish stocks, carbon storage in seabed sediments (although this is highly uncertain) and through the cultural value to people in Scotland of managing a healthy marine environment.

There is high uncertainty in the monetary valuation of these benefits, and robust values are not available to support cost-benefit analysis. See Section 7 for more detail.