Second year of Hemlock Looper Moth (Lambdina fiscellaria) outbreak returns to North Vancouver in larger numbers

Just as we saw last September (2019), North Vancouver has received a large influx of Hemlock Looper Moths (Lambdina fiscellaria) flocking towards bright lights at night, and plastered along buildings and foliage during the day. We know this is the second year of an outbreak of Western Hemlock Looper Moths, with the insects population spiking every 11-15 years on the coast and every 20 years in the interior of British Columbia. The Hemlock Looper Moth outbreak is said to last between 3-4 years and now coincides with an outbreak of Phantom Hemlock Looper which saw its last outbreak more than a decade ago.

Although neither of these species pose any risk to human health, they do pose a risk at high populations to forest health. During their caterpillar stage they feed on coniferous trees and can decimate forests when there are large enough populations. Primarily, the moths feed on Western Hemlock trees but since there are not enough in North Vancouver to support this outbreak, they have attacked Douglas Furs and Cedars as well. The North Shore forests have already begun to see the effects from this outbreak, with areas of trees turning brown/red and some completely stripped. One of the areas that this is visible is along the Capilano Watershed, where you can see large patches of brown and dying conifers.

With impacts visible surrounding North Vancouver's watersheds, I wonder if there is any potential impact to the water quality if large numbers of trees die off as a result of this outbreak?

Sources: https://www.cbc.ca/news/canada/british-columbia/significant-looper-moth-outbreak-threatens-north-shore-trees-1.5717863 https://www.citynews1130.com/2020/09/10/looper-moth-outbreak-taking-over-metro-vancouver/ https://globalnews.ca/news/7327963/swarms-of-western-hemlock-looper-moths-invade-parts-of-b-c-south-coast/ https://www.leonetwork.org/en/posts/show/02EF3CE4-681A-4C26-83A5-37AE4F4962D6