The environmental record of the Loch Fyne salmon farms – Part 3

Executive Summary – Salmon & Trout Conservation Scotland – 2018 revision – Permission Guy Linley-Adams

Azamethiphos use on Loch Fyne in 2016 – 2017

69. Azamethiphos is an organophosphate pesticide, which works by interfering with the transmission of nerve impulses. It is used in fish farming (as Salmosan) to control external parasites, particularly sea lice.

70. After use, azamethiphos remains dissolved until it is broken down into non-toxic derivatives, for which a decay half-life of 8.9 days has been determined17. This means azamethiphos remains active for some time after treatments have finished on fish farms and treated water has been released into the wider sea loch.

71. The effect of repeat organophosphate doses on non-target organisms, such as wild crustaceans, with insufficient recovery time between doses, is to progressively depress acetylcholinesterase enzyme activity, leading ultimately to mortality.

72. Azamethiphos was used very extensively indeed on the Loch Fyne fish farms in 2016 to the end of the production cycle in early 2017.

73. The table below shows the reported18 use of azamethiphos on Loch Fyne farms as against the 24hr limits contained in the CAR licences which are designed to protect against the effect of repeat exposure, without sufficient recovery, to organophosphates. The right hand column shows the minimum number of days the farm must have been treating with azamethiphos to stay within its CAR licence:

Capture table 1Capture table 2

74. The number of days per month each farm must have treated using azamethiphos to stay within each farm’s respective CAR licence ranges from 2 days to 17 days.

75. The data suggest that many Loch Fyne farms treated 9 or more times a month through the summer and autumn of 2016. Total use of azamethiphos on Loch Fyne by The Scottish Salmon Company between May and November 2016 was 66 kilogrammes.

76. Assuming there was no breach of CAR licence conditions by any farm, and given the half-life of azamethiphos, the number of days of bath treatment with azamethiphos on the Loch Fyne farms that is implied across the ten farms represents an almost continuous exposure of the wider loch and its wildlife, including highly sensitive wild crustaceans, to environmentally significant concentrations of azamethiphos in the summer and autumn of 2016.

77. This has been reported to SEPA, which has responded that:

“we would agree that the number of days treatment per month which has been reported at some sites, warrants further investigation….In the first instance we will focus our investigation on those sites in your Loch Fyne table which have reported 10 or more azamethiphos uses in a single month. It may take some time to collect the necessary level of detail from the operators, but I will provide you with an update on our findings when they become available”.

78. Given the status of Upper Loch Fyne and Loch Goil as a Marine Protected Area (MPA), as Scottish Natural Heritage (SNH) describes it, “designated to protect an assembly of seabed habitats, these long narrow sea lochs are home to the spectacular fireworks anemone, brightly coloured flame shells and the ocean quahog – one of the longest lived animals on the planet19”, this level of use of an organophosphate should be of serious concern to SNH.

79. The conservation objectives and aim of the MPA are “to recover the flame shell bed and to conserve the protected features of the Upper Loch Fyne and Goil MPA”. Protected features include burrowed mud; flame shell beds; horse mussel beds; ocean quahog aggregations; sublittoral mud and specific mixed sediment communities – many of which contain species that will be sensitive to organophosphates. Small crustaceans are also important prey species, forming part of the marine diet of sea trout.

80. SEPA reported in September 2017 that it considers that “the reason for some sites showing a higher number of treatment days is a direct result of this 24hr licence limit being complied with. As an example, a site comprising 12 cages which is limited in such a way as to allow only 1 cage to be treated in any 24 hours may, if fully stocked, need 12 days to complete a treatment across the whole site; whereas a similarly sized site at which 1 cage can be treated every 3 hrs could in theory be treated over a 2 day period. in some cases this treatment may need to be repeated and as can be seen from the data in some cases this has resulted in treatments being repeated over several months”20.

81. This level of use of organophosphates contrasts rather dramatically with what SEPA stated in 2005, in its Fish Farm Manual, that “effective environmental protection is promoted by a co-ordinated approach to Crown Estate leasing and SEPA consenting that seeks to prevent development of sites which will need to depend upon routine and prophylactic chemical use” to control sea lice.

Surveys of pollution and damage to the seabed under Loch Fyne fish farms

82. All fish farms must carry out a benthic survey every production cycle under the conditions of their CAR licences granted by SEPA. As SEPA states in its Fish Farm Manual the purpose of this monitoring is “to assess the ‘health’ of the benthos surrounding proposed and existing fish farms… to examine this risk to the local environment”21.

83. These surveys are largely required to ensure there is sufficient pollution-tolerant fauna on the sea bed under and immediately adjacent to fish farms to ‘turn over’ and degrade the organic wastes (uneaten fish food and fish faeces) produced by the hundreds of thousands of farmed fish above.

84. SEPA will categorise all surveys into ‘satisfactory’. ‘borderline’ or ‘unsatisfactory’ depending on the level of pollution and damage to the sea bed under any fish farm. SEPA states that a “borderline” classification is “indicate(s) that a site is close to having an unsustainable impact on the environment”

85. An “unsatisfactory” classification is “an indication that the emissions arising from the site in question are of a scale that is beyond the assimilative capacity of the local environment. This classification may relate to impacts on benthic fauna or sediment chemistry, unacceptable infeed medicine residues concentrations, or a combination of these parameters”22.

86. On Loch Fyne, the last three surveys at each farms are shown below:

Capture table 3Capture table 4

87. As can be seen, the most recent surveys show Quarry Point and Ardcastle are ‘unsatisfactory’. Note that Ardcastle is one of the farms seeking to increase its permitted biomass in 2017 (see below).

88. Over the last three surveys, only 4 of the 10 Loch Fyne farms have recorded satisfactory benthic surveys each time, calling into serious doubt that the current permitted biomass of farmed fish on Loch Fyne, as a whole, is sustainable, solely from the perspective of benthic impact.

Mortalities suffered at Loch Fyne farms

89. Data on monthly level of mortalities of farmed fish submitted to SEPA by The Scottish Salmon Company suggests that sea lice on the Loch Fyne farms were not only a problem for wild fish.

90. The data on mortalities of farmed fish experienced across the ten Loch Fyne farms shows a strong correlation between on-farm sea lice numbers and mortalities being experienced in the farms.

Capture STCS graph

91. Over the ten farms in Loch Fyne, SEPA data shows that the cumulative tonnage of mortalities – the weight of dead fish that have been removed from the cages during the month, not including fish that have been harvested as production23 – reached 2,420 tonnes in the production cycle to mid-2017.

92. For comparison, this figure is greater than the permitted biomass of any of the ten farms on Loch Fyne and is roughly twice the permitted biomass of the Glenan Bay, Tarbert South, Gob a Bharra or Quarry Point farms.

93. While it is difficult to estimate how many fish this equates to, if an assumption is made that the average weight across all Loch Fyne farms in October 2016 was about 3kg24that would suggest that approximately 200,000 farmed fish died in Loch Fyne fish farms in October 2016 alone.

94. Over the full two year production cycle, it is likely that mortalities on Loch Fyne exceeded one million farmed fish. This indicates that the management and husbandry of the Loch Fyne farms is not what it should be at the currently permitted biomass. This is unlikely to be positive for wild fish populations.

Applications in 2017 to SEPA to expand Loch Fyne farms

95. Despite the many problems on Loch Fyne, in 2017, The Scottish Salmon Company has made applications to SEPA for variations of authorisation at Tarbert South, Ardcastle and Ardgadden fish farms CAR/L/1010476, CAR/L/1010775, CAR/L/1010817 to allow them increase the biomass of farmed fish allowed at those farms even further.25

96. In 2018, the company has also applied to increase the biomass at Rubha Stillaig CAR/L/100089126.

97. These applications would allow the following increases:

Existing max biomass  |   Proposed biomass  |  % increase

Tarbert South                                          1030                                 1568                            52

Ardgadden                                               1696                                 2381                            40

Ardcastle                                                  1372                                 1752                             28

Rubha Stillaig                                           741                                   840                              13

98. S&TCS has objected, given the available evidence above, and has argued strongly that SEPA should not grant these applications and has asked SEPA to consider revising downward the current permitted biomass across Loch Fyne as a whole, in accordance with its wider duties and, specifically, its duty and power to review, per Regulation 21 of the Controlled Activities Regulations27.

99. As at 25th March 2018, no decision has been made by SEPA on the above applications, but it is worth noting that since the first wave of applications was made, the Ardcastle farm has recorded an unsatisfactory benthic report, which, in itself, would appear to make permitting an increase in biomass at that farm untenable.

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