Inner Bay: The spring and fall trends in waterfowl use on the Inner Bay have been opposite (Figure 8.41). Waterfowl use in the spring has increased substantially since the 1970s, while fall use has declined considerably since the 1970s. This can be attributed largely to increased numbers of diving ducks spending the day off the south shore of Long Point during the fall (when surveys are flown) and returning to the Bay at night, probably to feed (Figure 8.48 and 8.49). The reason for these opposing trends is unclear at this time, but may have something to do with disturbance (see section 8.3). Increased spring use of the Inner Bay can be attributed primarily to increased scaup numbers, while decreased fall use is attributed to declines in several species, especially Canvasbacks and Redheads. Decreased fall use may also be attributed to the fact that large portions of the Inner Bay were baited during the 1970s, a practice that has been actively discouraged since that time.

Big Creek Marsh: While the Big Creek Marsh has experienced overall declines in total waterfowl use since the 1970s (Figure 8.43), the proportion of waterfowl use has increased for most species assemblages since that time (Figures 8.48 to 8.53). While spring use has been somewhat erratic since the mid-1980s, there has been an increasing trend since 1993; this is particularly true for dabbling ducks (Figure 8.50). While fall use has declined since the 1970s for many species, particularly dabblers (Figure 8.51), numbers have remained very stable since the mid-1980s.

Long Point Management Unit (Crown Marsh): After recording large numbers of waterfowl using the Management Unit in 1975, this area received very little spring use until 1992 (Figure 8.44). Since 1992, spring use has been increasing steadily and almost reached mid-1970s levels by 1997. Spring dabbling duck and Tundra Swans numbers, in particular, have increased since the 1970s. Fall use of the Management Unit has declined slightly since the 1970s, but numbers have remained fairly stable throughout the 1980s and 1990s. Declining fall numbers can be attributed to reduced numbers of dabblers using the area (Figure 8.51)

Long Point Company Marsh: Of the seven sub-areas monitored, this marsh has experienced the most drastic declines in the total waterfowl use (Figure 8.45). Total waterfowl numbers and the proportion of birds relative to the other sub-areas has declined during both spring and fall. The fact that there have been substantial declines during both spring and fall suggests that hunting disturbance has not been the ultimate cause of these declines, particularly since fall dabbling duck numbers have remained quite high (Figure 8.51). It has been suggested that reductions in waterfowl numbers have been caused by the degradation of marsh habitats during high water levels over the past several years (Knapton 1997). However, the area receives very high Tundra Swan use during the spring and fall (Figure 8.52 and 8.53) which, through aggressive interactions or resource competition, may have precipitated the declines in duck numbers.

Long Point National Wildlife Area: Waterfowl use of this area is quite variable from year to year, but there has been an increasing spring and fall trend since the mid-1980s (Figure 8.46). While the proportion of Long Point's waterfowl that use this sub area has not changed in the spring, it has increased during the fall, particularly for dabblers (Figure 8.51). This can be attributed to the fact that between 5,000 and 10,000 birds are regularly recorded on Bouck's Pond during fall surveys. While it is unknown to what extent birds are foraging on this pond, the small size of the area and the extreme abundance of waterfowl would suggest that it may be very important as a refuge from disturbance. Fall Tundra Swan use has also increased substantially since the 1980s (Figure 8.53)