PROPOSED FIELDWORK ASSOCIATED WITH PETITCODIAC PROJECT 2003

1. Monitor water temperature in the drainage.
   
   
   Place temperature sensors in:
   
   
   • the upper ends of the Pollett, Anagance, North and Little rivers and Turtle Creek;
   • the lower end of each river;
   • near Salisbury on the main Petitcodiac;
   • at mid-impoundment;
   • at the causeway in the impoundment on the surface and near the bottom;
   • downstream of the causeway in the tidal portion of the river.

   Download data monthly.
   
   

   Reason: Water temperatures will be monitored to compare with historical data if available, and to provide a baseline record if historic data are not available. It would help the investigators comment on the suitability of the freshwater habitat for fish production by different species. It would provide data on the temperature difference in the water upstream versus downstream of the causeway that is encountered by fish traveling past the causeway. The presence of the saltwater wedge at the bottom of the impoundment would be detected with the sensors on the bottom and the top of the impoundment near the causeway.

2. Monitor Atlantic salmon smolts as they move through the impoundment to determine timing or delay and success of passage. Compare with timing and passage success from an un-impounded river such as the Big Salmon River for which smolt-tracking data are available.

   Reasons: It is uncertain whether the impoundment results in an elevation of mortality rates of Atlantic salmon smolts during their downstream migration to the ocean compared with the rates if the causeway were not in place. There are two potential pathways for this increased mortality. One is physical delay due to the presence of the pond and a decrease in water flow rate. Mortality would result from high temperature effects, or from unknown factors related to the delay itself (e.g. lack of synchronization with forage supplies in the ocean). This pathway has been demonstrated in the case of hydropower reservoirs. The other potential pathway involves predation by small mouth bass and potentially chain pickerel. The impoundment creates still water habitat that is suited to bass production. The population of this predatory fish species is higher than it would be if the causeway were not present. Bass predation may also be increased by physical delay of downstream smolt migration.

   To mitigate against these potential negative effects, a gate management strategy has been developed to flush smolts from the system by strongly drawing the impoundment down at night when the smolts are running. However, there is no mechanism to predict when to draw the impoundment down, and there is no method to determine whether the mechanism is effectively achieving its goal.

   Therefore, to investigate these questions, Inner Bay of Fundy smolts that are available for research purposes would be surgically implanted with hydroacoustic tags. They would be released into the middle reaches of the Little and Pollett rivers. They would be tracked at receiver stations at the Salisbury train bridge in the upper end of the impoundment, at mid-impoundment, at the causeway and downstream of the causeway. Other receiver stations will be operated this year by American researchers. Therefore, the smolts would potentially be tracked by their receivers also.

   The smolts will be released on Friday, May 16. On Tuesday, May 20, the upper-most receiver near Salisbury would be checked to determine the progress of the fish. The number of tagged fish that have progressed to this point will be reported to DFO. If the device has recorded an acceptable number of fish having passed Salisbury, the impoundment will be drawn down to facilitate the downstream migration of the smolts. The stationary receivers will be checked periodically, to determine what proportion of the smolts have emigrated to different points within the impoundment, or have, in fact entered the marine environment.

   In addition, upon a request from DFO, four so-called pre-grilse will be implanted with tags. Pre-grilse are very large juvenile salmon that were retained in the hatchery one year after they would normally have been stocked as smolts. They will mature this fall, but DFO would like to know what their behavior would be if they were stocked into freshwater in the spring. If they migrate to sea, they would presumably grow to a normal-sized grilse, and, because of their larger size, they might have a survival advantage over smolts. If they remain landlocked, the pre-grilse would be of little value. The tagging of these four fish would allow a determination to be made of the probable value of this stage of hatchery-reared salmon.

3. Trap netting in the impoundment 3 nights every two months to document anadromous and resident fish.

   Reason: Document the fish community of the impoundment, and determine whether the gate opening strategy and fishway have successfully passed upstream migrants. Compare these with recent DFO fish sampling efforts. Take temperature data concurrently to document the conditions under which the fish are surviving. Note the tidal levels in the days that preceded the sampling effort. If commercial fisherman is fishing this year, obtain these results as well. This activity will provide better knowledge of the fish community for full-cost accounting.

4. Electrofishing boat in impoundment one day every two months to document presence of fish species.

   Reason: Related to the proceeding Activity #3, this would be an additional method of determining the fish community of the impoundment and the effectiveness of upstream fish passage. All of the same associated data would be acquired. This activity will provide better knowledge of the fish community for full-cost accounting.

5. Monitor fishway trap periodically while it is in operation during the spring and fall.

   Reason: Determine effectiveness of fishway in passing upstream migrants. The trap would be operated under various tidal conditions and monitored to document the results. DFO will advise on timing of monitoring. This activity will provide better knowledge of the fish community for full-cost accounting.

6. Drift netting in lower estuary for 2 nights every second month to document presence of fish.

   Reason: Document the fish community of the Petitcodiac Estuary. Co-ordinate with the timing of historic shad runs. This might be supplemented with data from ongoing “commercial” shad fisheries. Water temperatures, salinities and tidal ranges would be documented. This activity will provide better knowledge of the fish community in the estuary and Shepody Bay for full-cost accounting.

7. Fishing in estuary for fish from the littoral zone.

   Reason: Document shoreline fish community. Compare with recent data from DFO. Comment on the quality of the habitat under status quo conditions by evaluating fish community. Water temperatures, salinities and tidal ranges would be documented.
   
   In the lower estuary, beach seining would be employed. In the region immediately downstream of the causeway, if beach seining is not practical, minnow traps would be set to document the fish community there. (This community has not been documented to our knowledge.) This information would be used to comment on the effects of the “status quo” situation. This activity will provide better knowledge of the fish community for full-cost accounting.

8. Visit smelt spawning tributaries upstream and downstream of causeway for four nights to determine success of smelt spawning run.

   Reason: Determine whether gate-opening strategy is successful in passing smelt upstream. Smelt is the main species that it is hypothesized the gate-opening strategy is successful in passing. In the spring, mud has not yet accumulated in the Gunningsville to the causeway corridor, and smelt are thought to pass upstream through the gates as the tidal level approaches and exceeds that of the impoundment. This is a barometer for the potential effectiveness of the strategy for other species. (i.e.: If the strategy does not work for smelt, it is probably ineffective for other species as well.) This activity will provide better knowledge of the fish community for full-cost accounting.

9. Evaluate the Recreational Fishery in the Impoundment

   Reason: To acquire current data on the total activity in the recreational fishery on the impoundment. The data would be used to estimate the economic value of the fishery for full-cost accounting purposes. Several methods using existing data are under consideration.

Schedule of Field Activities - 2003