Marine Harvest (Scotland) Ltd. Garry Fish Farm. Production Increase Proposal 2017

Transcription

1 Marine Harvest (Scotland) Ltd Garry Fish Farm Production Increase Proposal 2017

2 Loch Garry Fish Farm Production Increase Application Marine Harvest currently has a CAR licence to produce 102 tonnes of salmon smolt per annum at Loch Garry Fish Farm. The company is applying to increase the consented annual production by 20%, which is a 20.4 tonne increase, to a total of 122 tonnes. This increase would support the company s ongoing expansion plans which are vital to allow us to continue to compete with our global competitors and thus gain further investment into Scottish fish farming. Fish farming operations have existed in the loch for over 30 years and there have been no loch chemistry issues during that entire period. Figure 1. Garry fish farm (NH ) Consent History Marine Harvest farms within Loch Garry have held consent to produce 102 tonnes of salmon smolt per annum since Prior to this (since early 1980 s) the loch held a total consented annual tonnage of 85 tonnes. Until 2007, when the operations were consolidated into one location, the tonnage was produced from 3 sites within the loch. An application was made in 2011 to increase the production from 85 tonnes per year to 102 tonnes per year. This was granted in 2012 on the basis that the modelled effect of the increase did not result in total phosphorus concentration increasing to levels which would risk degradation of the WFD classification or the oligotrophic status of the loch. Loch Garry Environmental Conditions ( WFD) Loch Garry is currently classed as Good under the terms of the WFD and has been since 2012, with the latest reported total phosphorus ( TP) value from SEPA s sampling regime being 5.58ug/l. OECD classifies lochs as oligotrophic if they have p levels between 4ug/l and 10ug/l. As far as MHS are aware, SEPA have not carried out site specific macrophyte sampling in Loch Garry in any recent years. A survey performed by Ecus in 2016 (report and

3 data appended to this document) has confirmed that the latest macrophyte classification should be high. The Ecus report also notes that from the results of the survey it would appear that there are no discernible negative impacts on the loch as a result of the fish farm. Phosphorus Monitoring MHS has contracted the University of Stirling to independently monitor phosphorus levels in Loch Garry since Samples were taken twice per year until 2005 at which point the frequency of the regime was increased to bi-monthly to provide 6 sampling episodes per year. From the outset the sampling has been designed to provide an indication of levels throughout the entire loch and therefore samples are taken from a spread of locations as shown in Figure 2. At each location samples are gathered from 0m depth and 5m depth. Figure 2. Sampling locations within Loch Garry. Yellow = University of Stirling, Orange = SEPA SEPA also carries out sampling on Loch Garry, taking a sample once per month from a single sample point shown in Figure 2. MHS commissioned data analysis specialists TL Science to statistically examine the two datasets and compare the Stirling dataset against the SEPA dataset ( report appended to this document). TL Science identified the following conclusions: Both datasets contain a large amount of variation when looking at data from individual sample locations. There is no evidence for any overall year on year change or trend in phosphorus level in Loch Garry according to either dataset. This also means that there is no evidence of any change in phosphorus level brought about by the production increase in The two sampling regimes are not directly comparable due to the differences in their designs in terms of sample locations, replicate numbers and frequency of sampling. An argument can be made that the Stirling sampling regime is more likely to reflect a robust mean of the overall phosphorus levels throughout the loch. Multiple sampling sites, as used by Stirling, would be better able to capture the natural and experimental variability and thus provide a more representative indicator

4 of phosphorus levels; the single site sampling method used by SEPA would be less robust. Figure 3 shows the mean monthly phosphorus levels in Loch Garry since January 2009; the data suggests a downward trend. The 2011 application calculated ( using OECD equations for management of eutrophication of waters) that the additional phosphorus load arising from the proposed tonnage increase at the time, 17 tonnes) would be 0.81ug/l; this level of increase is not apparent in the sampling data from the University of Stirling. This suggests that an increase in production tonnage is not directly linked to increased total phosphorus within the loch. It also suggests that model predictions are overly precautionary and actual levels of increase, if any, are likely to be far less. Using the same equation to calculate the theoretical TP increase with the 2016 proposed additional tonnage suggests an increase of 1.04ug/l would occur. If added to the SEPA reported loch level of 5.58ug/l then this would lead to a new level of 6.62ug/l, which is well within the site specific TP boundary of 8.00ug/l for Good to Medium classification. Figure 3. Monthly phosphorus levels in Loch Garry since January 2009 (Results from University of Stirling) SEPA has a sampling dataset from a single sample point location within the loch; the results of this are shown in Figure 4. The results show a large degree of variation which may be skewing the trend; this could also be indicative of a very large amount of natural variation. The Stirling data by comparison covers a larger number of sample locations and displays much less variation.

5 Figure 4. Monthly phosphorus levels in Loch Garry since January 2009 (Results from SEPA) Plus+ Modelling The James Hutton Institute ( JHI) produced a report on the current phosphorus status of the loch and its capacity to support additional input. This work was carried out by using the Plus+ model which was developed by the JHI based on OECD derived eutrophication management calculations and land use/slope data. The modelling methodology was designed specifically to mirror the approach used by SEPA to assess applications for additional phosphorus loading. Loch Garry is currently graded as having good WFD status for phosphorus with a current level of 5.58ug/l. The boundary between good and moderate status is 8.00ug/l. The JHI notes that there is capacity for an additional phosphorus input of 3,273kg per year before the classification of the loch would change from good to moderate. However, given that Loch Garry is upstream of a number of other waterbodies, a limit of 1,750kg per year was proposed by the JHI report in order to preserve the status of downstream lochs ( Oich, Ness, Abban, Douchfour). The application was considered based upon this lower limit and therefore the tonnage (20.4 tonnes) applied for is conservative in terms of how it relates to environmental capacity as it would only add an additional 147kg of phosphorus per year. Phosphorus Inputs: FCR and Diets Fish farming feed conversion ratios ( FCRs) have improved massively since the farm was installed in the 1980 s and also since the farming operations were consolidated into a single location within the loch. This improvement is due to advances in feed composition, equipment, site management and feeding practices. Phosphorus content of feed has also been reduced over the years as feed composition has been improved; Table 1 shows the makeup of example diets fed at MHS loch sites based on a mean phosphorus content of 1%. This diet has already proven successful, retaining high levels of FCR performance and fish

6 quality. Marine Harvest proposes to use diets of 1.1% phosphorus content ( or less) at the Garry site. Table 1. Example feed types and phosphorus content Feed Type Proportion of Site Feeding Phosphorous Content Level Total Nutra Advance 2 (1.2mm) 2.6% 1.50 Nutra Advance LP % mm Nutra Advance LP % mm Nutra Advance LP 50 3mm 55.2% 1.00 Average 1.01 Diets have improved so that they are more attractive and accessible to the fish, and so that the proportion retained within the fish and converted to growth is as high as possible. Feed delivery has vastly improved so that pellets can be supplied to the fish in an incredibly accurate manner; both in terms of time keeping and spatial distribution. The continuing improvement of automated systems for feed delivery continues to allow reduction of FCRs as human resources can be increasingly used for enhanced levels of control rather than physical labour. The consolidation of the Garry sites, which was granted by SEPA in 2007, is one of many site improvements which resulted in better site management and equipment. Key factors in this include better control over fish health and welfare and also better behaviour monitoring particularly via investment in underwater camera systems). These measures have all played a part in improving FCR and reducing phosphorus input to the environment. Table 2 shows calculations for the amount of phosphorus discharged into the loch when considering various different scenarios. As mentioned in the paragraphs above, the current and forecasted FCR, is lower than it was historically and this has been reflected in the calculations. The figure highlighted in red shows the projected phosphorus input arising from the proposed additional tonnage. This represents 8% of the available capacity within the loch and therefore is extremely conservative.

7 Table 2. phosphorus inputs from Marine Harvest s fish farming in Loch Garry. Input per Tonne Based on Current FCR Garry Potential Additional Capacity to Garry Proposed Additional Input from 20.4 tonne Production Increase Before Degrading Loch Oich downstream) Phosphorus in feed: Feed Conversion Ratio (FCR) Max Production 1,000 20,400 kg per annum) 243,100 Proposed increase in production) Feed Input ( kg per 1,100 22,440 annum) 267, 410 Total P in Feed kg) 2,942 P entrained in fish kg) Note: this is based on 40. 5% of phosphorus within feed being remaining within the fish Amount of P discharged ( kg per annum) P discharge per kg production ( kg) 7.2 1, ( note: this figure is only 8% the available capacity noted in the cell to the left) Medicine Use The proposed increased tonnage of fish arising from this site will not require an increase in medicine consent quantities as there are currently no plans to increase the number of pens at the site.