Take Home Points

Geoduck populations appear to be the exception to the rule with climate change. Many marine organisms are suffering physiological stress, decreased calcification rates, and overall lower fitness. Geoducks, however, reflect a success story with their higher recruitment rates and steady fitness levels with acidifying, warmer oceans. Here are some take home points you should remember:

• The ocean is changing due to a changing atmospheric climate. This has resulted in warmer ocean temperatures and increasing acidity.
• An acidic ocean has been problematic for many calcifiers, but this trend has not been observed for geoducks (thus far at least). 
• Some hypotheses to explain the geoduck's success with climate change include:
• Geoducks have greater plasticity rates, i.e. can  respond more readily to changes over the short term.
• Geoducks may not be constrained by antagonistic genetic correlations, i.e. their genes are not holding them back from adapting.
• Geoducks may actually prefer warmer oceans because they have higher recruitment success rates in higher temperatures. This has allowed them to extend their habitat range farther north.
• The value of the geoduck stock is very profitable and Washington state's economy is greatly dependent on it. Research to date seems to demonstrate that this industry is not under immediate threat. However as the ocean continues to increase in acidity and becomes warmer geoduck populations needs to be continually assessed to make sure they remain healthy. 

Much is still unknown about the future of geoduck populations with a changing ocean. It is unclear how their food source will be affected, if predation rates will increase (or decrease), and if disease will effect geoduck population size and fitness. It is also possible that there is a temperature or pH threshold that will occur in the future and past which geoduck population fitness will decline. These factors could all greatly impact the success rate of geoduck populations and therefore need to be monitored. Research needs to continually conducted to ensure geoduck populations continues to be successful with a changing ocean because otherwise there could be large-scale negative economic and biological repercussions. This hot topic needs to monitored so the geoduck can continue to pass the acid test!