Chapter & Verse recent additions

Suffolk long-line fishery LT1020 Jolene: Wider impact

Wed, 8 Apr 2009 13:13:30 +0100

We use the FAO Technical Factsheets on the various methods of fishing used globally to provide a generic score for the wider environmental impact. This is scored out of five, best to worst practice, for the fishing method used, in this case FAO category 34, ‘set longlines’. We then consider local modifying factors, in this case for set longlines used in the Outer Thames, and finally consider variations up or down for the specific boat, in this case the Jolene.

3. Wider environmental impact
The wider environmental impact includes all aspects not directly covered by the status of the fish stocks and selectivity of the gear. So this includes habitat damage and issues such as deaths of marine mammals or seabirds. It also includes wider environmental impact such as fossil fuel use.

As described here, we judged the generic global score for wider environmental impact of set long-lines as ‘4, good’. The primary concern with unmodified long-lines is the capture of seabirds such as albatrosses, which grab and get hooked on the bait and drown.

As for our scoring of selectivity, we do not have the information about Outer Thames long-line boats in general to make a local modification, though we would be surprised if there were factors that resulted in a local score worse than the global generic.

On the Jolene, the main seabirds present during part of the period when lines were being shot were kittiwakes. These small gulls nibbled and occasionally flew up with the bait in the few seconds before the bait was carried below the surface. None were hooked, and our impression was that the gull’s gap was physically too small to make it easy to swallow the hook. It is possible that a diving bird such as a gannet might possibly get hooked. However, there are no colonies of gannets closer than Yorkshire, and in the winter the birds are widely dispersed and at low density in the Outer Thames.

Another (MSC certified) fisher who has long-lined in northern UK waters in the past also concurred that they could not recollect this being an issue in UK waters. So while we will monitor this issue, and seek opinions as part of our consultation, we do not believe that this will be a major issue.

We are unaware of marine mammals being at risk from these long-lines.

The seabed where this gear is deployed will be mobile sand or gravel, without surface fauna or flora. The seabed impact of anchors, ground-line and possible dragging in the current are therefore likely to be minimal.

The Jolene is a relatively high powered boat (according to the February 2009 UK register the sixth most powerful boat in the under 10 metre fleet). This allows her to go further offshore in the Outer Thames estuary, with the aim of accessing larger, older and more valuable fish. The fuel consumption will therefore be greater than most under 10 m boats.

Our initial opinion is therefore to give the Jolene long-line fishery a score of ‘5 - best practice’ for wider environmental impact.

How controversial?
It is possible that some may consider that further research needs to be done on seabird capture, and that fuel use is somewhat high to warrant a maximum score of 5, but overall we believe this score will like prove to be uncontroversial.

Suffolk long-line fishery LT1020 Jolene: Selectivity

Wed, 8 Apr 2009 08:50:20 +0100

We use the FAO Technical Factsheets on the various methods of fishing used globally to provide a generic score for selectivity. This is scored out of five, best to worst practice, for the fishing method used, in this case FAO category 34, ‘set longlines’. We then consider local modifying factors, in this case for set longlines used in the Outer Thames, and finally consider variations up or down for the specific boat, in this case the Jolene.

3. Wider environmental impact
‘Selectivity’ is about how selective the method is for catching the intended target - the species of fish. At one level, this is about avoiding species that are not targeted, targeted species being assessed under ‘stock status’.

However, it is also necessary to take into account selectivity with regard to the target species – here cod and thornback. This is important where a stock status is poor, but the particular method, if widely used, would play an important part in its recovery. The converse is also true – we would not want to support a fishery on a stock with good status where that measure risks depleting the stock.

As described here, we judged the generic global score for selectivity (i.e. of the range of fish caught) of set long-lines as ‘3, transitional’. This may well also be true for all Outer Thames long-line boats, which will likely target the same species as the Jolene—thornback and cod. However, without information on possible variation on the hook size and baiting practice between boats it is not possible to give an adjusted local generic score.

Selectivity with regard to non-target species is very simply assessed for Jolene’s longline fishery – other than cod, thornbacks and the occasional bass, very few individuals of other species are caught – partly a function of low species diversity in the Outer Thames, compared to somewhere like Cornwall, and partly the active selection of sites by the skipper to avoid other (less valuable) species.

With regard to cod and thornback we know that the Jolene uses large hooks, large bait (c.f the Yorkshire long-line fishery), and intentionally goes further out to sea, all with the aim of catching larger and older fish (c.f the graph comparing size of thornback caught by the Jolene against that caught by Outer Thames trawling earlier in this opinion).

Our initial opinion is therefore to give the Jolene long-line fishery a score of ‘4 - good’.

We don’t give it a score of ‘5-best practice’ because while the Jolene avoids the capture of smaller cod prevalent in trawled fish and with long-lines used in cod nursery areas, the FAO technical guidelines on long-lines suggest that gill nets offer the very highest level of control over the size of fish caught (note that Jolene switches to gill nets later in the season). This might become important, for example, if it is considered important to conserve a healthy stock of very large ‘mother cod’. In other words, this is some form of restriction on ‘maximum landing size’. At the moment, there are so few very large cod that this is somewhat academic: however the aim of good fisheries management should be working towards building up the numbers of larger fish, so this should already be in the mind of forward thinkers in the industry and managers. We say ‘this might become important’ because it may be possible for long-liners to avoid locations where ‘mother cod’ accumulate, either by active choice of location, or via the use of protected areas.

For the moment the initial aim should be to phase out all forms of fishing in areas where this inevitably results in disproportionate numbers of juvenile whitefish being killed. As the increased survival rate of these juveniles begins to build up the number of larger fish, this increase should partly be used to build up the age and size structure of the fish (i.e more older, larger fish), and partly–with due caution–to allow a gradual increase in the amount of those larger fish caught by fishers using responsible fishing methods. Long-lining has a positive part to play in such a strategy to—in effect—gradually increase the average size of fish landed.

For thornback, with regard to selectivity, it clearly catches larger fish than trawling, and also small thornbacks are returned, and due to the short soak times and lack of a swim-bladder, thornback survival is known to be good (from e.g. the Cefas Fisheries Science Partnership research). A proportion of thornbacks caught by long-lining will be immature and – as with cod – it is not clear that long-lining can be used as precisely as gill netting to target mature thornbacks, but it is not quite as important because the survival of returns will be good.

How controversial?
This long-line fishery is highly selective at avoiding non-target species, and this aspect should be non-controversial. However it is likely that people will also take into account how selective it is avoiding juvenile fish, or even whether cod or thornback fishing should occur at all. Some fishers will consider that trawling is no more harmful than long-lining, some on the environmental side will consider that no fishing should be targeting these species at the current time and with the current measures. We therefore anticipate that our initial opinion for selectivity, of ‘4 – good’ could be highly controversial.

Suffolk long-line fishery LT1020 Jolene: How controversial?

Wed, 8 Apr 2009 07:44:18 +0100

1. Stock Status

How controversial?

We understand that our assessment of stock status of ‘1-worst case’, based on our acceptance of scientific advice that North Sea cod is in danger of collapse will likely be highly controversial with many fishers. They argue that they are encountering many cod in many areas. They also point out that landings and even their catches of cod will be depressed not because the stocks are low, but because they are doing all they can to avoid catching cod.

We nevertheless go with the scientific advice because, where sampling for cod is done in a standardised way, and consistently across the same sites, for many years, as done in research vessel monitoring, it is evident to us that the stocks are not just slightly less, but vastly depleted compared to historical levels, even if one discounts the exceptionally high stocks of cod (and haddock) in the 1970s. This is also evident from the graph of spawning stock size going back to the 1960s and beyond. That graph shows that fishing mortality has now been substantially reduced, but also–unfortunately–that we may have been ‘behind the curve’ with measures that were always ‘too little, too late’. The pain may now have extended far longer, and been far worse, than a complete closure, implemented, and funded for a 3-4 of years in the 1990s, would have been (as seen from recovery of stocks in the Wars).

We also go with the scientific advise, because egg surveys back up the fish surveys, and because both tagging and genetic analysis demonstrate that local sub-stocks exist, and need to be accounted for in management – something not yet done. It appears that one genetically distinct sub-stock - that off Flamborough Head appears to have been extirpated. This was initially replaced by migration before declining once more to very low levels, with some scientists now describing this in terms of a ‘collapsed stock’. The sub-stock in Southern Bight is also under more pressure than other more northerly elements amongst the North Sea cod. This sub-stock will feature in the catches of the Jolene.

Fishers have certainly been seeing more cod in the last couple of years. This is because of the relatively good ‘year-class’ of 2005. This however, appears to be of very modest size compared to historical records, even as recently as the 1990s. Moreover many of the 2005 year class will have been caught when still immature (only half of cod of 50 cm will be capable of spawning, but nearly all of those of 75 cm and larger – many cod caught, particularly in trawls and as by catch in the small mesh Nephrops trawls will have been smaller than this). In the mid 1990s there was a far bigger year class than in 2005, but because catch levels were then increased, and unselective fishing methods continued, this was fished out, preparing the ground for the disastrous state of cod stocks in this decade. We should not let history repeat itself.

Another reason for supporting the scientific advice is that the North Sea, even with increasing sea temperatures and other factors, if properly managed, can still support stocks of cod far larger than now, sustaining environmental and economic benefits.

Our support of long-line fishing is also likely to be highly controversial with some environmentalists and sea anglers. We support long-lining, and other selective methods, as a practical demonstration that techniques exist that – if widely implemented – would be part of the solution because they catch cod of larger average size (50–75 cm) than whitefish trawls, which are larger in turn than the whitefish caught in small-mesh Nephrops trawls. We understand that, because of the scale of the harm being done by other fisheries, supporting long-lining or other selective techniques such as gill netting will not, of themselves build up cod stocks. We also understand that the averaged size and age of cod should be increased still further than those currently caught by these methods, and also ensuring that sufficient large, fecund, ‘mother cod’ are built up. Our judgement is that the scale of these selective fisheries is currently relatively small, and the benefit of supporting carefully selected vessels, and demonstrating that alternatives exist, is greater than the adverse effects of their contribution to current cod mortality. The current priority, we believe, is ensuring that far more juvenile fish survive to breed.

We also note the scientific advice that protected areas – while certainly justified and required for other reasons – may be a blunt tool for the cod sub-stock in the Southern Bight because (based on tagging surveys) this sub-stock appears to be wide ranging, going into – and being caught – in areas in the central and northern North Sea.

For thornback, the scientific assessment in this part of the North Sea is that the stock is stable, possibly increasing. This is a change from earlier advice, that there should be no targeted fishery for any skates or rays. We understand the concerns about range contraction of thornback in the North Sea, and would not support the expansion of quotas of thornback while methods, such as trawling, which capture smaller thornbacks are permitted. However, traditional targeted fisheries for thornback, using methods such as long-lining that capture larger individuals, should be supported, and the benefits from increasing juvenile survival used both to build up the numbers of larger fish, and gradually increase the average size and– with due caution– the catches of larger fish.

As with cod, we would like to see those methods brought to an end, and for the stocks of older fish built up with the general aim that the average size of fish in the North Sea is gradually increased towards historic levels. As with cod, we note the results of tagging surveys that indicated that thornbacks that breed in the Outer Thames estuary range widely in the southern and central North Sea and occasionally beyond.