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flSHERIESRESEARCHROARDor 8!0L0GICALSTATlON, ST. JOliN'S. NEI'IFOUNDlAND. OANAOA FISHERIES RESEARCH BOARD OF CANADA MANUSCRIPT REPORT SERIES No. 1037 TInE Bleached Kraft ~1i11 Effluent near Pictou, N.S. anu its Effect on the ~Iarine Flora anu Fauna with a Note on the Pictou Co. Lob5ter Landings AUTHORSHIP D. J. Scarratt Establishment Biological Station, St. Andrews, N. 1:1. Dated November 1969 This se;ies includes unpublished preliminary reports and doto records not intended for general distribution. They should not be referred to in publicotionswithout clearance from the issuing Boord establishment and without cleor indication of their manuscript status. FISHERIES RESEARCH BOARD OF CANADA MANUSCRIPT REPORT SERIES No. 1037 TITLE Bleached Kraft ~lill Iiffluent near Pictou. N. S. and its Effect on the ~larine Flora anJ Fauna with a Note on the Pictou Co. Lobster Landings AUTHORSHIP n. J. Scarratt Establishment Biological Station, St. Andrews. N. Il. Dated Novemher 1969 This se;ies includes unpublished preliminary reports and data records not intended for general distribution. They should not be referred to in publicotions without clearance from the issuing Board establishment and without clear indication of their manuscript status. BLEACHED KRAFT MILL EFFLUENT NEAR PICTOU, N. S. AND ITS EFFECT ON THE MARINE FLORA AND FAUNA WITH A NOTE ON THE PICTOU CO. LOBSTER LANDINGS By D. J. Scarratt In September 1967, a 500 ton/day bleached kraft mill became fully operational at Abercrombie Point, Pictou County, N. S. Freshwater effluent is piped at the rate of 20 million gal/day into a settling pond where it is held for 4 days before entering Boat Harbour. After an estimated 40-day retention period, it escapes through a diffuser pipe into the head of Boat Harbour inlet which opens into the sea about 1 mile southeast of the entrance to Pictou Harbour (Fig. 1). Res idua1 surface drift in the area is of the order of 1.5-3.5 miles per day to the east (Lauzier, 1965) and the effluent is carried in that direction in a narrow stream which keeps close to the shore past Mackenzie Head and is visible at least as far as Roaring Bull Point 3 miles distant. Earlier studies (Scarratt, 1969; Sprague and McLeese, 1968) had indicated no likelihood of immediate or direct effects of the effluent upon lobsters. There were, however, complaints from fishermen that lobsters were considered to be leaving the area. In response to this, brief surveys were made on May 26 and 27 and August 19-21, 1969. This report describes these surveys, presents an account of the lobster landings in Pictou County since 1952 and concludes that the area exposed to high concentrations of BKME is relatively small and there is no evidence for attributing declining lobster landings to the effluent. METHODS Survey 1 - May 26-27, 1969 This survey was in two parts: a) Hydrographical survey Beginning at Boat Harbour dam, a series of surface water samples were taken from 11 stations along the shore (Fig. 1). The following properties were measured : dissolved oxygen content by the modified Winkler method, specific gravity, temperature and concentration of effluent (Table 1). The latter was determined colorimetrically by comparing each sample with a series of standards made by mixing known proportions of effluent and clean sea water taken several miles offshore. Salinity was calculated from specific gravity and temperature records using Knudsen tables. -Z- Five stations were occupied further offshore (Fig. 1) and water samples taken at the surface, bottom and several intermediate depths. Specific gravity, temperature, Oz content and effluent concentration were determined as before. Two of the stations were 1/4 and l/Z mile off the mouth of Boat Harbour and the other three were at 1/4- mile intervals off Mackenzie Head. Onshore winds prevented the research vessel from moving closer inshore. b) Biological survey A brief, visual macroscopic examination was made of the flora and fauna at each of the 11 shore stations, and several photographs were taken (Fig. Z-6). These observations are summarized in Table 1. Scuba dives were made and the sea bed examined at Mackenzie Shoal (Station E, Fig. 1) and also off Logan Point. Depth at each station was about 5 m. Lobster traps were set in both areas. It seemed possible that Mackenzie Shoal would receive some effluent but unlikely that Logan Point would be affected and this area was regarded as a control. Survey Z- August 19-Zl, 1969 This survey similarly was in two parts: a) Hydrographical survey This extended from above Boat Harbour dam throughout the course of the effluent stream into the open sea and for a distance thereafter, and was coupled with spot checks at various places outside the apparent effluent stream (Fig. 6, 7). Clement weather and the use of a small boat permitted samples to be taken in the centre of Boat Harbour entrance, and at several places very close to shore along the open coast. Temperature and salinity were determined as before, and dissolved oxygen concentration was determined in the more concentrated parts of the effluent stream. Colorimetric determination of effluent concentration was made for samples from all stations. All samples were retained and their pH and U. V. absorption spectra were subsequently measured by Dr. V. Zitko at St. Andrews. Concentration (C) of effluent for each sample (n) was calculated from (1) where A is the U. V. absorbance of that sample. 0.035 is Z50n -3- the A of clean St. Andrews sea water and 8.7 is the A ZSO ZSO of undiluted effluent from the surface of Boat Harbour lagoon (sample D). Concentrations are expressed as percentages. Surface samples were taken at all stations, together with samples near bottom and occasionally at an intermediate depth in or near the apparent effluent stream (Tables 3, 4). b) Biological survey Underwater observations of the sea bed were made at Mackenzie Head and Roaring Bull Point inside the effluent stream and at Cole Point, Logan Point and Seal Rock which are outside it. Seal Rock and Roaring Bull Point are about equi­ distant from Boat Harbour, upstream and downstream respectively. RESULTS Survey 1 (Spring) - Hydrography and littoral observations The sample taken from Boat Harbour above the dam (station 1) was regarded as 100% effluent and was used as a colour standard. It contained no oxygen (Table 1). There was no apparent flora or fauna in the lagoon. On the downstream side of the dam (station 2) there was considerable mixing of effluent with sea water at the outfall; the salinity had increased to l8%., colour had decreased to 40%, and dissolved oxygen content was 30% of saturation. One stickleback (Gasterosteus acuZeatus) and one other unidentified larger fish were seen. At station 3 there were several live isopods high on the rubble bank but only the empty shells of barnacles and periwinkles could be found on adj acent rock outcrops (Fig. 2). Closer to the mouth of the harbour entrance (station 4) the mudflats did not appear to support any clams or other species. The small lagoon (station S) inside the entrance . s only flooded by the tide occasionally and the low salinity and low colour indicate that it receives drainage directly off the higher land behind. Dissolved oxygen concentration was high (80\ saturation). There were several unidentified fish in the lagoon. By the sandy bank just inside the harbour entrance on the west gt~:id~o~~~rh:~~o~~o~~~r;~~ea~~e~~ ~~~~e~iv:O~a~~a~~~~r~~~o~~ri_ winkles on the rocks (Fig. 3) and isopods, amphipods and various polychaetes under them. There was a narrow tongue of clean sea water spilling into the entrance over the sand bar from the west (station 7, Fig. 4) and presumably some clean water entering under the outgoing, less dense, partially diluted effluent. On the east side (station 8), salinity was lower and colour higher than on the west side, indicating that the effluent was being held on shore by the wind, but higher O concentration (90% saturation) shows 2 that wave action and turbulence on the beach were promoting oxidation of the effluent. There was considerable foam (Fig. 5). In the cove between Powell Point and Mackenzie Head, effluent concentration was down to 4% and at Mackenzie Head it was 2%. At Roaring Bull Point the effluent was barely detectable in small samples but the sea was plainly discoloured. The shore­ line between the cove and Roaring Bull Point appeared devoid of deleterious biological effects due to the effluent; however, there was a detectable odour to the water and some foam along the strand line even at Roaring Bull Point. The effluent stream was not followed any further to the east. Under conditions existing during the May survey--moderate onshore breeze and falling tide--the effluent was plainly visible as a darker streak of water never more than 250 m wide and frequently less, extending from the mouth of Boat Harbour easterly to Roaring Bull Point. No effluent was detectable at the offshore - stations and oxygen concentrations were high at all depths (Table 2). At other stages of the tide, effluent extends in a westerly , direction towards, and possibly part way up, Pictc,lU Harbour (Lawrence and Neu, personal communication). With offshore (southerly) winds it will probably extend in a thin layer further offshore. Survey 2 (Summer) - Hydrography There had been no gross observable changes wi thin Boat Harbour or the entrance since the May survey. The beaches were still stained and discoloured up to high-water mark and the effluent stream outside Boat Harbour entrance was still demarked by a precise line separating it from clean sea water beyond.

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