The LA Times reports that last winter's El Niño triggered unprecedented erosion across California's coast.
The article highlights research analyzing last year's El Nino storm track that brought us one of the best winter surf seasons on record.
This new research confirms what we observed in Ventura: the combination of large waves and drought drove unprecedented levels of winter shoreline retreat.
 |
| the "cove" at Surfers Point in Ventura post El Nino winter beach, 5-6-2016 |
 |
| the "cove" at Surfers Point in Ventura summer beach, 6-28-2016 |
The drought is just one factor in sand-starved beaches. “...we dam the rivers for flood control and say, ‘Holy crap, the sand’s not getting to the beaches anymore.”
But last year another force was in play; rising sea levels. The paper states that "Water levels anomalies of 7–17 cm above normal were measured across the US West Coast during the El Niño winter of 2015–2016, similar to anticipated global mean sea-level increases expected within the next few decades."
This El Niño may have been a big one, but it may become “the new normal”
Which raises the question;
How will rising sea levels affect surfing in the future?
This topic is explored in a new paper titled Using local knowledge to project sea level rise impacts on wave resources in California published in the journal Ocean & Coastal Management.
This research concludes:
 |
| Map of California surf-spot vulnerability, Reineman et al |
- Sea level rise will likely impact the quality of surf-spots; in California that impact will be a net reduction in overall wave quality at current surf-spots.
- Vulnerability of surf-spots to sea level rise varies geographically, with some surf-spots and some regions experiencing more significant reductions in wave quality; due to sea level rise, roughly 18% of surf-spots evaluated here are Threatened by drowning and 16% are Endangered; 5% could improve.
- Surfers' local ecological knowledge of waves constitutes a measureable source of data about environmental condition and variation.
As sea level rises locally, surf-spots that break at low tide, or medium tide, or high-tide will be increasingly and sequentially inundated: the water will simply be too deep for them to experience their best conditions.
And perhaps most relevant to our local situation, in areas where landward migration of the beach is not permitted, either through seawalls or natural marine terraces, the beach will be "drowned."
 |
| Factors influencing surf-spot vulnerability, Reineman et al |
This research relied upon surveys of thousands of surfers, who often have the best understanding of local conditions. The paper concludes that;
Given the vast economic and cultural importance of surfing, these conclusions suggest that coastal managers should not only give credence to the wave knowledge of surfers, but also take wave quality and vulnerability into consideration, especially when planning coastal armoring, beach nourishment, or other developments, whose impacts to natural coastal processes could affect waves.
On this blog:
Surfer Magazine cover
C-St Ventura - cobble and erosion Dec 2015
Surfers Point - first real test
Surfers' Point emergency revetment
References:
El Niño triggered unprecedented erosion across California's coast, LA Times Feb 14, 2017
Extreme oceanographic forcing and coastal response due to the 2015–2016 El Niño. Barnard, P. L. et al. Nat. Commun. 8, 14365 doi: 10.1038/ncomms14365 (2017).
http://www.nature.com/articles/ncomms14365
Using local knowledge to project sea level rise impacts on wave resources in California, Dan R. Reineman, Leif N. Thomas, Margaret R. Caldwell, Ocean & Coastal Management. Volume 138, 15 March 2017, Pages 181–191
