4.0 Inshore Fisheries: Background Information
4.1.1 This section of the report provides the following information on inshore fisheries 10 :
- target species and methods;
- fisheries management/regulatory framework; and
- the potential environmental effects of fishing.
4.1.2 At the end of 2011, there were 2,095 active vessels 11 in the Scottish fishing fleet. The fleet is dominated by vessels 10 metres and under (1,470 or 70%), with a total power of 78,000 kWs. There were 625 vessels over 10 metres (30% of the fleet), with 80% of the fleet's total power (309,000 kWs).
4.1.3 Between 2005 and 2011 there was an overall decrease in vessel numbers:
- The number of vessels in the 10 metre and under fleet decreased by 6%
- The number of vessels in the over-10 metre fleet decreased by 13%
4.1.4 Some 75-80% of the Scottish fishing fleet fishes in inshore waters. Most of these vessels are 10 metres or under in length.
4.1.5 The 625 vessels over 10 metres were involved in the following sectors:
- demersal (229);
- pelagic (24); and
- shellfish (372).
4.2 Target Species and Methods
4.2.1 The Scottish fleet comprises three main sectors: pelagic; demersal; and shellfish.
4.2.2 Pelagic fish move about throughout the water column and often occupy the open waters between the coasts and the edge of the continental shelf in depths of 20-400 metres. In Scotland the main pelagic species caught are herring and mackerel. Other species include blue whiting ( Micromesistius poutassou), sprat ( Sprattus sprattus) and horse mackerel ( Trachurus trachurus).
4.2.3 Demersal fish (also known as whitefish or roundfish) live and feed on or near the bottom of the sea. The main species caught are monkfish, haddock and cod. Other species include whiting, saithe, ling and blue ling. A variety of demersal species are taken as by-catch, including plaice, lemon sole, dogfish, skates, witch, megrim, redfish, dab, hake, and turbot with lesser quantities of catfish, forkbeard, grenadier, tusk, halibut, turbot, Greenland halibut, brill and pollack.
4.2.4 Shellfish comprise crustaceans and molluscs. Crustaceans include the Norway lobster ( Nephrops norvegicus), lobster ( Homarus gamarus), edible crab ( Cancer pagurus) and velvet swimming crab ( Necora puber). Other crustacean species fished include the shore crab (Carcinus maenas), the squat lobster ( Munida rugosa and others) and crayfish ( Palunirus elegans).
4.2.5 Molluscs include both bivalves and gastropods. Bivalves include king scallop ( Pecten maximus), queen scallop ( Aequipecten opercularis), razorfish ( Ensis spp.), cockle ( Cerastoderma edule) and a range of other bivalve species (including those described as surf clams). Gastropods include whelks (Buccinum undatum) and periwinkles (Littorina littorea).
4.2.6 The 10 metre and under fleet is dominated by vessels catching shellfish (1,416 vessels; approximately 96%). The key shellfish species for the inshore fleet is the Norway lobster, or Nephrops norvegicus. Scallops, brown crabs and lobsters are also important. 12 Of these 1,416 vessels, 1,285 (nearly 90 per cent) used creel fishing as their main fishing method in 2011. The remainder mostly used trawling. Table 7 provides more detail. Figures 3a and 3b show the different gears in the water column.
Table 7. Number of active Scottish-based vessels by main fishing method and length (2011)
|Main fishing method||≤10m||> 10m||Total|
|Demersal single trawl||18||139||157|
|Demersal pair trawl||-||19||19|
|Demersal gill nets||4||5||9|
|Demersal twin/multi trawl||-||16||16|
|Shell fishing by hand||34||4||38|
Figure 3a. Gears in the Water Column 13
Figure 3b. Scallop Dredging Gear 14
4.2.7 There is also a small finfish fishery, which in previous years included both pelagic and demersal fishing. However, in 2011, the focus was on the demersal sector, pursued by 54 vessels (Table 7).
4.2.8 Of the over-10 metre fleet, 229 and 24 vessels were involved in the demersal and pelagic sectors respectively in 2011. Shellfish were targeted by 372 vessels (some 60%) during this period. The dominant fishing method for shellfish was trawling (177), followed by creel fishing (118) and mechanical dredging (71).
4.2.9 Target species, fishing methods and locations include:
- Nephrops are found in muddy sediment, and the main inshore Nephrops fisheries are in the Firth of Forth, Moray Firth, North Minch, South Minch and Clyde areas. Fishing is undertaken by both otter trawls and creels; on the west coast there is an extensive creel fishery, for example.
- Scallops are found all around Scotland, and are generally fished with dredges by both local and nomadic vessels.
- Fishing for crab and lobster with creels takes place all around the coast, and crabs are also fished in some offshore areas northwest of Scotland.
- Trawling for squid, creeling for whelks, hydraulic dredging or diving for razorfish and surf clams, and collecting cockles by hand or mechanical means all take place in various locations around the coast of Scotland.
- Finfish also feature in inshore landings and local Nephrops trawlers operate a small pair trawl fishery for sprat in the winter in some west coast sea lochs. 15
Figure 4 shows the overall shellfish landings from around Scotland's coasts in 2011.
4.2.10 In terms of fishing fleet location, approximately one-third of the 10 metre or under vessels in Scotland are based on the west coast, another third on the east coast, and the remaining third in Shetland, Orkney and the Western Isles. 16
4.3 Fisheries Management Measures
4.3.1 A number of mechanisms are used to manage Scottish fisheries, including restricted licensing, quotas and minimum landing sizes, and days at sea/closed areas. The following paragraphs summarise these mechanisms.
Inshore Fishing (Scotland) Act 1984
4.3.2 Since 1984, inshore fisheries in Scotland have been regulated primarily through the Inshore Fisheries (Scotland) Act 1984, which enables Ministers the powers to prohibit combinations of the following in inshore waters ( i.e. within 0-6 nautical miles):
- All fishing for sea fish
- Fishing for a specified description of sea fish
- Fishing by a specified method
- Fishing from a specified description of fishing boat
- Fishing from or by means of any vehicle, or any vehicle of a specific description, and
- Fishing by means of a specified description of equipment
4.3.3 UK fishing vessels engaged in commercial sea fishing are required by law to be registered with the Registry of Shipping and Seamen, part of the Maritime and Coastguard Agency. Licences authorise the sea areas in which a vessel can fish and the species that can be targeted. Restrictive licensing has been used as the main tool to control UK fishing opportunities to meet European Union ( EU) regulations for sustainable fisheries management. 17
4.3.4 Most stocks exploited are managed under the Common Fisheries Policy ( CFP) by the European Commission and an important part of this management is the use of Total Allowable Catch ( TAC). Member States are allocated a TAC quota for different species and areas which are intended to allocate fish resources and to control the amount of fish removed each year. 18
4.3.5 Nephrops is the only shellfish species targeted by UK fishers with a quota, and this applies to inshore waters (0-6 nautical miles) and waters further offshore (6-12 nautical miles). (The Northern prawn or pink shrimp - Pandalus borealis - is also managed by quota, but there were no landings of this species in 2011 by Scottish vessels.)
Minimum Landing Size
4.3.6 Another regulatory mechanism is minimum landing size ( MLS) which is set out by the EU in Annex XII of Regulation 850/98 ( Appendix 2). For both finfish and shellfish, undersized animals are not to be retained, transhipped, landed, transported, stored, sold, displayed or offered for sale. In addition, undersized animals must be returned immediately to the sea. 19 Minimum landing size regulations exist chiefly to ensure sufficient mature individuals in a species are able to survive in order to reproduce.
Figure 4. Shellfish landings (tonnes) by areas of capture ( ICES rectangles)
Management of Crab and Lobster
4.3.7 Crab and lobster landings are not limited by quota. However, landings are restricted to those commercial fishermen whose licence allows them to catch crabs and lobsters (those holding a Shellfish Entitlement) and are subject to minimum landing size restrictions.
Spatial Management Measures
4.3.8 A number of sea areas in offshore waters are already closed to fishing to protect vulnerable marine ecosystems such as cold water corals on the Rockall Bank and Darwin Mounds. In addition, fisheries in some areas are limited or prevented altogether in order to protect breeding seabird populations. An example of this is the precautionary north-east UK sandeel fishery closure (Article 29a from Council Regulation No 850/98), which limits fishing on most of the Firth of Forth sandeel grounds and covers both inshore and offshore waters (Figure 6 includes closures around the Scottish coast). In Shetland, some 20 km 2 has been closed to scallop dredging to protect biogenic reefs 20 . National measures can be put in place by Scottish Ministers but outside 6 nautical miles other EU Member States are not obliged to observe these closures.
4.3.9 Schemes exist for the accreditation of fisheries as sustainable, in terms of stocks, environmental impact, and effective management. Examples include the scheme operated by The Marine Stewardship Council (Box 1) and the Responsible Fishing Scheme developed by the Sea Fish Industry Authority (Seafish) 21 .
Box 1. Marine Stewardship Council's Fishery Accreditation Scheme
The Marine Stewardship Council ( MSC) is an independent, global non-profit organisation which operates a third-party, voluntary fisheries certification and eco-labelling scheme. The MSC blue eco-label gives assurance that the product comes from a sustainable fishery. Fisheries are assessed in accordance with the MSC standard for fishing. This standard is based on three overarching principles: 22
These principles are supported by thirty-one detailed criteria against which fisheries are assessed.
4.4 Environmental Effects of Fishing
4.4.1 Fishing is known to result in a number of environmental effects, both direct and indirect. These are summarised in Figure 2 and discussed in the following paragraphs.
4.4.2 All fishing results in the removal of individuals from the population, which can have consequences for population sustainability. It also has indirect consequences for the availability of food for prey species such as cetaceans, birds and other fish.
4.4.3 The overexploitation of stocks can lead to depletion of stocks to unsustainable levels. It is important that fish stocks are managed effectively so that they can continue to provide a resource for future generations and safeguard the diversity of the marine ecosystem on which they depend. 23 In some instances specific management measures may be required to promote the recovery of over-exploited stocks. Since 2007, for example, Scotland has operated a system of "real time" closures of sea areas where there are concentrations of cod; this is designed to help the continuing recovery of cod stocks in the waters around Scotland. 24
4.4.4 The use of mobile fishing gear has become a source of concern, particularly because of the observed effects on:
- the seabed. Dredging for scallops and trawling for shellfish and demersal species modifies the seabed. The duration of effect depends on the method and the nature of the substrate affected.
- benthic communities. The dredging and trawling methods referred to above may kill or injure benthic animals and destroy and/or damage habitat. Again, the duration of effect depends on the method and the nature of the affected communities.
- non-target species, particularly removal. 25 Scottish Sea Fisheries Statistics identifies a number of species caught in this way, including lemon sole, pollack, etc.
4.4.5 Any fishing gear will affect the flora and fauna of a given location to some degree, but the magnitude and the duration depends on several factors including gear configuration, towing speed, water depth and the substrate over which the tow occurs. 26 The long-term viability of some fish and shellfish populations could also be threatened if essential fish habitat is degraded. 27
Discards and bycatch
4.4.6 As well as removing target species, fishing may also capture non-target species, including fish, seabirds and cetaceans (this is commonly known as bycatch).
4.4.7 Discards are the proportion of a catch of fish which is not retained on board during commercial fishing operations and returned to the sea. There are a number of reasons for discards: undersized fish below the legal minimum landing size; species with low or no market value; and/or a lack of quota.
4.4.8 Discards can include "bycatch", a term usually used for fish caught unintentionally in the fishery. This can also include other untargeted species such as seabirds and cetaceans. One of the most serious threats facing small cetaceans is incidental capture or "bycatch" in fishing nets. 28 Council Regulation 812/2004 lays down measures concerning incidental catches of cetaceans by fisheries and requires Member States to report certain cetacean bycatches. 29 It has also been reported that perhaps the most serious threat to seabird populations worldwide is accidental mortality as a result of capture and drowning in fishing gear. 30
4.4.9 Discarding can impact on the environment, through:
- increased mortality of target and non-target species; and
- the alteration of food webs by supplying increased levels of food to scavenging organisms on the seafloor and to seabirds. 31
The impact of discarding varies by species: some species including whitefish, such as cod and haddock, have low survival rates when discarded whereas other species including sharks or crustaceans (such as Nephrops) may have higher survival rates. 32 Scotland actively promotes a fisheries management system which allows vessels to "catch less, land more". 33
4.4.10 Gear technology can improve the selectivity of the catch and therefore reduce bycatch. For example, the main bycatch species from Nephrops trawling are whiting, haddock and cod. 34 Experiments have shown that the different behaviours exhibited by these species in the Nephrops trawl fisheries can be exploited through net design to improve the selectivity of trawls. 35 Fish behaviours in relation to fishing gears have been the subject of research at Marine Science Scotland ( MSS) for many years. 36
Competition for resources and disturbance
4.4.11 In some instances fishing can lead to competition for resources and disturbance of species. Intertidal fisheries, for example, may cause disturbance to birds if they occur during low tides in areas where shorebirds feed and roost. Disturbance may exclude birds from areas they use for feeding, roosting or other activities. 37 In addition, there is evidence that in areas where traditional hand gathering of cockles takes place, even a reduction of less than 25% of available cockles will be enough to reduce spring oystercatcher numbers. 38 Closure orders to support seabird populations have been progressed in certain areas in Scotland, e.g. the sandeel fishery in the Firth of Forth environs.
4.4.12 Trawling and dredging can change the physical habitat and biological structure of ecosystems and can therefore have wide-ranging consequences. Mobile gear can reduce benthic habitat complexity by removing or damaging the actual physical structure of the seafloor and causing changes in species composition. The reduction of physical structure in repeatedly trawled areas can result in lower overall biodiversity. The effects of mobile gear on benthic habitats depends on the susceptibility of the habitat and on gear type used. Some habitats are extremely sensitive to disturbance; maerl beds, for example, are slow to recover from disturbance due to extremely low growth rates. 39 Recovery times vary according to the intensity and the frequency of the disturbance, the spatial scale of the disturbance and the physical characteristics of the habitat (sediment type, hydrodynamics). Superimposed on these human-related alterations are natural fluctuations caused by storms or long-term climate change, for example. 40
4.4.13 A silt cloud is also created by dredging, which settles in the surrounding area. Sediment settlement has been recorded as far as 21m away from the dredged area. 41 Another study found that sediment plumes may settle to form layers (75 mm thick), which may smother the surrounding area. 42 This changes superficial sediments and sediment organic matter, affecting the availability of organic matter for microbial food webs. 43
4.4.14 Potting and creels have relatively little impact on benthic habitat when compared to trawling and dredging. However, this depends on the number of creels and their location (including intensity of fishing effort). There are currently no limits on the number of pots and creels that can be placed at one time.
4.4.15 Derelict fishing gear, sometimes referred to as "ghost gear", is any discarded, lost, or abandoned fishing gear in the marine environment. This gear has the potential to continue to fish and trap animals, entangle marine mammals, and act as a hazard to navigation. Fisheries remain one of the worst sources of marine litter and there are mixed views of the harm that this litter does to the environment. 44
4.4.16 Fishing methods that affect the seabed can also result in the damage and/or loss of historic environment features. Conversely, such sites have the potential to be a hazard for other marine users, for example, through snagging fishing nets and obstructing navigation. 45
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