Additional Bottom-up Projects

In addition to the above projects, two additional projects were developed in 2015-2016.  One is related to monitoring of ocean acidification of the Salish Sea (including evaluation using the Citizen Science vessels) and the effect of acidification on the marine ecosystem within the Strait of Georgia; and a second project is related to the incidence and impact of Harmful Algae Blooms on juvenile Pacific salmon.  The incidence of these blooms appears to be increasing and may contribute to reduced survival of salmon.

Harmful Algal Program – Canada

Team: Svetlana Esenkulova (PSF), Nicky Haigh (HAMP)

Objectives: To determine the prevalence of harmful algal blooms in the Strait of Georgia and their impact on juvenile salmon.

Background: The harmful algae program was developed during 2014 with a pilot study in Cowichan Bay. This program is now fully implemented with collections of phytoplankton taking place throughout the Strait of Georgia in the citizen science program. Samples are being collected from stations from February to November, primarily from surface waters, but at a number of depths (surface, 5, 10, 20m) from 3-4 priority stations. Phytoplankton data collected are biomass estimation, identification and enumeration of dominant species, % of constituent groups (diatoms, dinoflagellates, silicoflagellates, raphydophites, nanoplankton, zooplankton), and identification and enumeration of all harmful algae. The water quality data collected concurrently with the phytoplankton samples will be used to determine the conditions that appear to promote the development of harmful algal blooms.

Lab studies to assess the conditions that promote development of harmful toxins are currently under development. The field project may be augmented in 2017 with studies to assess whether juvenile fish are able to actively avoid blooms in marine waters.

Status: Based on thousands of samples (collected bi-monthly from February to October at ~80 sites) in 2015 and 2016, they have unprecedented, high-resolution data on phytoplankton dynamics in the Strait of Georgia. Phytoplankton biomass and composition were strikingly different in 2015 and 2016, and appear to be closely associated with nutrients and environmental parameters. There is a clear synchrony in phytoplankton dynamics across the Strait, however it differs significantly on location-scale. They observed effects of harmful algae on juvenile salmon in Cowichan Bay in 2014, 2015, 2016 and the effects were consistent with these confirmed on salmon farms in BC and papers worldwide.

2015

An unusually early spring phytoplankton bloom in 2015 was associated with higher than normal water temperatures in the Strait of Georgia and early snowmelt. Lower summer biomass and dominance of diatoms (low dinoflagellates contribution, silicoflagellates, and raphidophytes) were associated with lower than usual river discharges and rainfall in summer. The year of 2015 was unusually quiet in terms of harmful algal blooms: there were no toxic blooms to salmon throughout the sampling period; moderate and high levels of Chaetoceros convolutus/concavicorne (mechanically harmful to salmon) were observed in Cowichan Bay, Baynes Sound, Campbell River, Lund, Powell River, and Irvines Sechelt at the end of May and beginning of June.

2016 

In 2016, the spring bloom was recorded several weeks later than in 2015; it was comprised by a mixture of species (Thalassiosira spp., Skeletonema costatum, Chaetoceros spp.), whereas the spring bloom of 2015 was comprised mostly by one species (Skeletonema costatum). The phytoplankton composition (in terms of groups: diatoms, dinoflagellates, etc.) in 2016 was more normal then in 2015. The year of 2016 was somewhat unfavorable in terms of harmful algal blooms: there were elevated levels of non-skeletal Dictyocha (toxic to salmon) observed after periods of heavy rains in some areas, moderate blooms of Rhizosolenia setigera (mechanically harmful), low-moderate levels of Heterosigma akashiwo (toxic) in few areas in late August/early September samples. There were several non-harmful blooms (Ditylum brightwellii, coccolithophores) observed in summer.

Observing non skeletal Dictyocha in the field Cowichan Bay, summer 2016

Status:

Based on thousands of samples (collected bi-monthly from February to October at ~80 sites) in 2015 and 2016, they have unprecedented, high-resolution data on phytoplankton dynamics in the Strait of Georgia. Phytoplankton biomass and composition were strikingly different in 2015 and 2016, and appear to be closely associated with nutrients and environmental parameters. There is a clear synchrony in phytoplankton dynamics across the Strait, however it differs significantly on location-scale. They observed effects of harmful algae on juvenile salmon in Cowichan Bay in 2014, 2015, 2016 and the effects were consistent with these confirmed on salmon farms in BC and papers worldwide.

2015

An unusually early spring phytoplankton bloom in 2015 was associated with higher than normal water temperatures in the Strait of Georgia and early snowmelt. Lower summer biomass and dominance of diatoms (low dinoflagellates contribution, silicoflagellates, and raphidophytes) were associated with lower than usual river discharges and rainfall in summer. The year of 2015 was unusually quiet in terms of harmful algal blooms: there were no toxic blooms to salmon throughout the sampling period; moderate and high levels of Chaetoceros convolutus/concavicorne (mechanically harmful to salmon) were observed in Cowichan Bay, Baynes Sound, Campbell River, Lund, Powell River, and Irvines Sechelt at the end of May and beginning of June.

2016

In 2016, the spring bloom was recorded several weeks later than in 2015; it was comprised by a mixture of species (Thalassiosira spp., Skeletonema costatum, Chaetoceros spp.), whereas the spring bloom of 2015 was comprised mostly by one species (Skeletonema costatum). The phytoplankton composition (in terms of groups: diatoms, dinoflagellates, etc.) in 2016 was more normal then in 2015. The year of 2016 was somewhat unfavorable in terms of harmful algal blooms: there were elevated levels of non-skeletal Dictyocha (toxic to salmon) observed after periods of heavy rains in some areas, moderate blooms of Rhizosolenia setigera (mechanically harmful), low-moderate levels of Heterosigma akashiwo (toxic) in few areas in late August/early September samples. There were several non-harmful blooms (Ditylum brightwellii, coccolithophores) observed in summer.

Citizen Science data on phytoplankton collected in 2015 and 2016 was presented at the DFO State of the Pacific Ocean (SOPO) meeting in Sydney attended by 200 people from government and academia. For the first time the SOPO Report contains fundamental information on the in-situ phytoplankton at high resolution scale (thousands of samples collected bi-monthly from February to October at ~80 sites).

http://waves-vagues.dfo-mpo.gc.ca/Library/40617944.pdf SOPO report

2017

In 2017 Citizen Scientists collected about 2000 phytoplankton samples (bi-monthly from February to October at ~80 sites) across the Strait of Georgia. While only about half of the samples are analyzed as of October 2017, there are already some interesting results lining up: very low but an unusually widespread presence of Dinophysis spp. (cause of Diarrhetic Shellfish Poisoning) in July and beginning of August, lot of Alexandrium spp. (cause of Paralytic Shellfish Poisoning) in some areas, Dictyocha spp. (toxic to salmon) blooms in Irvine’s Sechelt, Powell River, Lund, and Galiano areas in late July through mid-August, and moderate concentrations of Rhizosolenia setigera (cause mechanical irritation to gills) in some areas.

Outcomes:

  • High-resolution, in situ data on phytoplankton dynamics in the Strait of Georgia, 2015, 2016, and 2017 has provided a solid foundation for understanding bottom-up control of zooplankton and herbivories fish dynamics (bottom-up control for salmonids). With an additional data from 2017 (a year not affected by El Nino), they will be examining links between phytoplankton and environmental characteristics in the SoG.
  • Studying effects of harmful algae on wild juvenile salmon in the Cowichan Bay 2014-2016 (top-down study) provided a body of evidence that wild salmon is negatively affected by harmful algae in the same way as the aquaculture salmon in BC (harmful algae directly affect salmon survival: toxic algae through acute or chronic toxicity and mechanically harmful algae through gill damage).
  • Known harmful algae are enumerated in every sample collected by the Citizen Scientists, one of the enumerated groups – species from genus Alexandrium. Most species of Alexandrium produce highly potent neurotoxins that cause Paralytic Shellfish Poisoning (PSP) and in very high concentrations can cause fish kills. PSP closures occur in the Strait every year which is a challenge for shellfish growers. In their study, based on over 1000 phytoplankton samples collected by the Citizen Scientists in 2015, they found that the location and season were the most important factors in Alexandrium distribution. Full report was published in Harmful Algae News, an Intergovernmental Oceanographic Commission’s newsletter, in March 2017. http://www.e-pages.dk/ku/1276/html5/
  • Unexpected outcomes: juvenile salmonids significantly reduced feeding and their diets were somewhat unusual during high biomass (very thick) non-harmful blooms.
  • Collecting data, observations, and analysis of phytoplankton dynamics (including harmful algal blooms) could potentially increase hatchery salmon survival through timing of the hatchery releases with favorable phytoplankton conditions. Continuing phytoplankton monitoring program (e.g. Citizen Science Program or smaller scale program in important to juvenile salmon areas) provides information (both bottom-up and top-down in terms of phytoplankton effects on juvenile salmon) that can improve the accuracy of adult returns forecasting and reducing uncertainty around the role of the marine environment in overall productivity.

Lessons Learned:

  • High resolution data could be used for establishing the links between environment-phytoplankton-zooplankton and understanding local food web interactions which in turn could enable evaluation of the role of bottom-up control of juvenile salmon survival
  • Phytoplankton dynamics in the Strait of Georgia are directly connected with the environmental conditions of the Strait (no stat yet but there are some obvious connections with Fraser River discharge and precipiation)
  • Phytoplankton dynamics in the El-Nino year 2015 were anomalous – very early and strong spring bloom, lower summer biomass, diatoms dominated throughout the whole sampling season
  • Phytoplankton dynamics in 2016 and 2017 – different time and species composition of the spring bloom, higher summer biomass, high abundance of silicoflagellates in some areas at the end of the summer, higher contribution of dinoflagellates then in 2015
  • Although there is a clear synchrony in phytoplankton dynamics, there are also some very substantial (logarithmic scale) regional differences
  • Numerous evidence that algal blooms and harmful algae presence directly affect juvenile salmon in enclosed embayment
  • Collected data on phytoplankton dynamics in the SoG through Citizen Science Program proved to be exceptionally cost effective and useful to various agencies

A New Component of the Citizen Science Program: Ocean Acidification Monitoring

Team: Wiley Evans, Alex Hare, Eric Peterson, Hakai Institute

In the summer of 2016 the Hakai Institute began a partnership with the Pacific Salmon Foundation’s Citizen Science (PSF-CZ) program to evaluate the potential for ocean acidification in the Strait of Georgia. Ocean acidification is the process of increasing the ocean’s level of acidity, termed its “pH”, and is caused by increasing amounts of carbon dioxide from the atmosphere dissolving into the ocean.

The effect of changing ocean pH on marine life differs widely between species and currently little information is available about the long-term consequences of such change on coastal environments. The seawater chemistry in coastal settings can also vary widely between nearby areas and over short timescales, adding complexity to the situation. The Hakai Institute and PSF are addressing this shortcoming in knowledge by combining their abilities to collect water samples and make seawater carbon dioxide measurements at locations throughout the northern Strait of Georgia (Figure 1). Scientists from Hakai’s Ocean Acidification Program will then use the measurements to determine how carbon dioxide behaves in the Strait of Georgia and to investigate the potential of ocean acidification in the region.

Figure 1. Left panel: blue circles represent where water samples for ocean acidification measurements were collected in the Baynes Sound, Desolation Sound, Sentry Shoal, and west Texada Island areas by the PSF’s Citizen Science program in the summer of 2016. Right panel: PSF’s Citizen Science crew collect water samples in the Desolation Sound area.

One of the key pieces of information produced by the Hakai and PSF partnership is how suitable the seawater conditions are for growth by marine shell forming animals, and how these conditions change on daily to monthly timescales. This information comes from the measurement of a water property termed ‘aragonite saturation state’, which changes when seawater carbon dioxide concentrations and pH level change. Measurements from the summer of 2016 show that saturation state conditions differ between areas of the northern Strait of Georgia, and change from month to month (Figure 2).

Figure 2. Aragonite saturation state in surface water of the northern Strait of Georgia in 2016. Coloured circles in the images represent saturation state values at those locations according to the colour bar at the right side of the figure.

The Hakai Institute partnered with the Pacific Salmon Foundation (PSF) again in 2017 to provide seawater measurements that track ocean acidification in the northern Strait of Georgia. The partnership began in 2016 and is based on the PSF Citizen Science Program’s small vessel fleet that regularly deploys marine sensors and collects water samples along regular routes throughout the Strait. Water samples for ocean acidification measurements are collected by the Citizen Scientists at 7 locations and are analyzed at the Hakai Institute’s Quadra Island Field Station located in Hyacinthe Bay, Quadra Island (Figure below).

Ocean acidification measurements produced from the PSF Citizen Science crews complement year-round high-resolution measurements made by sensors installed at fixed locations at Quadra Island, Sentry Shoal, and Baynes Sound. This sampling arrangement couples the large-scale context of water chemistry changes at the seasonal level with highly detailed measurements that provide deeper insight into the processes driving ocean acidification. Together, these efforts are providing new insight into the processes governing coastal ocean acidification, how those processes are connected across locations, and where the timing and location of sensitive conditions for marine species may exist within the Strait.

First, measurements from the northern Strait of Georgia demonstrated coherent seasonal transitions from late summer 2016 to mid fall of 2017 across both the mainland and Vancouver Island sides of the Strait.  Furthermore, most locations showed seasonally coherent carbonate chemistry that was also consistent with that determined from carbonate system sensors located at Sentry Shoal and Quadra Island. This consistency supports the value of such higher-resolution fixed sensor installations by demonstrating their applicability to the northern Strait region in general.

Secondly, these measurements provided the ability to construct a spatially resolved time series over the northern Strait of Georgia of the saturation state of carbonate minerals, which is an important water quality parameter for many marine shell-forming organisms. Locations where the saturation state values differed from those elsewhere in the region may indicate ‘hotspot’ locations of, or refugia from, low-pH seawater conditions that arise from both natural and climate change-associated processes and are typically adverse to marine shell forming organisms.

Lastly, the seasonal structure of the upper water column at each sampling location demonstrates a divergence in saturation state between surface and 20 m depths, reflecting a difference in the shell-forming conditions in these two environments. Both depths demonstrated similarly poor shell-forming conditions in early spring and late fall and good conditions during spring and early summer. However, conditions were much better in surface water and lasted much longer than those at 20 m depth during the spring and summer. For instance, while shell-forming conditions declined from good spring conditions to neutral (no tendency of carbonate minerals to precipitate or to form) in most locations by early July in water at 20 m, this decline was not observed until October in surface water.

The Hakai Institute: www.hakai.org

Ocean Acidification Program contact: Alex Hare, alex.hare@hakai.org

Quadra Island Field Station: 250.285.3134