Originally, there were four bridges along the causeway. The first one was over a small creek not far from the mainland. The next bridge over the Port Royal Ship Canal – a grand name for a channel dug through the marsh to allow the transport of logs to the bay. There was also a bridge south of the old Hamilton Big Creek Hunt Club (now the Canadian Wildlife Service buildings) and lastly a large bridge over the historic outflow of Big Creek, across from the Sandboy Marina. Only the Ship Channel (what everyone now calls Big Creek) remains.
On average, nearly 2300 car trips are made across the causeway every day between April and October (2005 data). Four times this number of cars crosses the causeway on summer weekends.
The Big Creek Marsh acts as a giant natural kidney for the entire watershed. Because the marsh now has only one outlet into Long Point Bay, sediment and pollution-laden water now flows directly into the bay instead of being purified by the marsh
Shoreline marshes require seasonal flooding and storm events to keep them healthy. With the causeway acting as a barrier, the health of the marsh is deteriorating. The causeway also limits fish access to the marsh and fishing in the bay would be better if the spawning areas were more readily accessible.
It is estimated that 10,000 animals die on the causeway annually, according to surveys by the Canadian Wildlife Service. Most are leopard frogs but 99 other species have been run over including rare and endangered species. Wildlife crossing signs and reduced speed limits seem to have had little effect.
So many turtles are being run over at Long Point that the causeway is now ranked the 5th deadliest road in the world for turtles. A recent study by CWS and the Long Point Waterfowl and Wetlands Research Fund has demonstrated that about 3% of passing cars intentionally try to run over wildlife, especially turtles and snakes. The perpetrators of these crimes are almost always men.