Red Tide Algae Bloom and other Water Problems in the
Greater Cabrillo Basin, San Pedro, CA

Cabrillo Inner Beach, Cabrillo Beach Youth Waterfront, Cabrillo Fishing Pier, Cabrillo Marinas, the West Channel and the 22nd Street Landing.

May 2012:  Very dense red/brown clouds were noticed circulating around the Cabrillo Marina, samples were taken to the Cabrillo Aquarium who reported the material to be a heavy concentration of flagellates; they were unable to identify the exact sub-species. This initial bloom dissipated within three days, no dead birds or fish were observed.

Upper Cabrillo Marina – Red Tide in foreground, green water in background.

 Red Tide in upper Marina, green water in background.

Sample Bowl - Red Tide Algae Bloom of August 2012

August 2012: Red Tide returns with vigor, dense red/brown clouds of blooming algae circulating throughout the Marina lasting for eight days, and then a few days later another bloom engulfed a large area around the Fuel Dock and the Docks along Berth 31 lasting for about a day. Above picture shows algae bloom in sample bowl.


Upper Cabrillo Marina – Red Tide in foreground, green water in background.

We obtained live samples daily and with time and practice were able to identify and photograph many microalgae dinoflagellates tentatively identified as Akashiwo sanguinea. This Algae Bloom sighting was reported to, who promptly dispatched a Lab Technician with a tow/drag net; the Technician acquired samples at two diverse locations within the Cabrillo Basin which were taken to the Marine & Environmental Biology Laboratory at USC where they were official identified as Akashiwo sanguinea, Japanese for “Red Tide”.

Dinoflagellates Akashiwo sanguinea*  (click the pictures above for short video clips)

Akashiwo sanguinea dividing - Right cell may be a Akashiwo host just after dividing?


This species is not in itself toxic but is associated with fish die-offs as a result of the dead blooms falling to the seabed where they are digested by bacteria, that process consumes oxygen thus lowers the dissolved oxygen content in the immediate water column causing fish therein to suffocate. There have been incidents reported of extensive seabird mortality caused by a surfactant-like protein derived from A. sanguinea, the material coated the birds feathers and neutralized the natural water repellency and insulation resulting in birds drowning.

In another report anchovy larva were observed ingesting this organism but not other dinoflagellates suggesting a preference for A. sanguinea. The Cabrillo Marina is a nursery for anchovy’s, We observed a school of about 1000 juvenile anchovy’s slowly swimming just below the surface the entire length of an algae bloom about 15’ wide extending up the Marina channel probably a few hundred feet, the anchovy school could have easily avoided or departed the bloom but stayed the course suggesting that anchovy’s per se feed on Akashiwo sanguinea.  During this bloom period no dead fish were noted in the Marina area, the dying cells dropped to the bottom over a wide area most probably reducing the dissolved oxygen levels but remaining in the safe range. A prevailing wind produced many small rafts of dense packed feathers which accumulated along the entire East rock wall alongside “K” docks in the new Marina. A few boat owners and “regulars” walking/jogging the Marina reported seeing several dead birds. The abnormal amount of floating feathers suggested there were additional birds having problems in the outer Harbor & Cabrillo Basin and possibly dead fish out there as well.

The day the drag/tow net samples were taken the dense visible bloom had completely dissipated, a water sample was taken off the Cabrillo Pier and the second off the 22nd Street Landing, two distant locations spanning the entire length of the greater Cabrillo Basin area, both sample showed high levels of Akashiwo sanguinea indicating this dinoflagellates species was well entrenched throughout the Cabrillo Basin suggesting additional bloom potential. Browsing many on-line papers, reports and studies on dinoflagellates and algae bloom there appeared a re-occurring theme: “A noted increase or spike in the flagellate’s population is usually preceded by an increase or spike in available nutrients”. Or said another way “these little guys have to very well feed before they bloom”. Over a period of four weeks we took water column and bottom samples at various locations around the Marina and tested same for phosphate and nitrate, principal nutrients for algae growth, and came up “0” suggesting the Marina area was not offering a free lunch, not a likely location to trigger a dinoflagellate bloom.

Studying the charts, wind and currents suggests that the bloom most probably originated in the Cabrillo Basin Shallow Water Habitat/Dredge Dumping Zone where daily dumping churns up the bottom, The Green expansion area (see Chart) has been undisturbed for many years; it is most likely rich in nutrients, upwelling’s from which may provide the necessary food resources promoting Red Tide/Algae Blooms.

Chart: Cabrillo Basin/L.A. Port Outer Basin. The Grey area is the original unfinished Shallow Water Habitat Zone, the Green area is the recent 50 acre expansion, the entire area will be raised to about -14/15’ MLLW using material dredged from the Main Channel. The Violet line is the tidal path thru the open-ended Main Channel, the path of least resistance; the Orange line is the tidal path to the closed-ended Cabrillo Area.

This Satellite View clearly shows dumping operations in the 50 Acre Shallow Water Expansion. The water depth within the Expansion Zone previously varied between 40 and 50 feet, it is now being filled to about 14/15 depth narrowing the previous deep wide 22nd Street/West Channel, further buffering the tidal flow (fresh sea water exchange) from the Ocean to/from the Marina, the Inner Beach and the CBYW Youth facility…

Dumping operations in the Cabrillo Basin, about 3.0 million cubic yards of dredge material
distributed over 250 acres. Completion 2013?  Cabrillo Inner Beach in the foreground.

Under certain conditions incoming tide, current and wind may propel sections of the bloom into the Cabrillo Marina, a period of time would be required for the algae cloud(s) to reach the lower Marina and then more time to reach the upper Marina and the 22nd Street Landing. The bloom clouds moving slowly and often thru wind whipped surface waters would lose much of their original density but remain dark enough to raise the eyebrows of resident boaters, a few of which expressed concern to a Marina Manager about starting their boat engines least the material foul the seawater filters?

Dredge laden sea foam from the dumping operation in the Basin carried into the upper Marina adjacent to the 22nd street Landing, an example of the ability of tide, wind and current to move surface material and bottom upwelling’s a considerable distance from the source.

It is highly probable that Akashiwo dinoflagellates have been blooming in the Basin on and off since the Shallow Water Habitat filling operation began many years ago but now are more common due to the intensified dumping program. As the Chart indicates and depending upon the timing of the tide most of the blooms probably were carried up the Main Channel or out to sea where they would quickly dissipate. Boaters and personnel working on the water most likely noticed changes in water color, a few dead fish, a dead seagull or a pelican, these sightings are usually written off as commonplace thus go unreported, It is only when the wind, tide and currents combine and propel large clouds of bloom into the Marina that it becomes visible to the public and is reported.

Ceratium  Polykrikos 

A few additional dinoflagellates found in Cabrillo Marina.


Cabrillo Pier, Cabrillo Inner Beach and the Cabrillo Beach Youth Waterfront:  As previous noted many years prior to the present on-going Main Channel Dredging and Dumping operation the Port of Los Angeles was engaged in a fill operation to raise the seafloor of a major section of the Cabrillo Basin to about 14’. This was but another not thought thru Federal Government sponsored program that was intended to provide a Shallow Water Habitat, supposedly a haven for coastal fish. In this instance the program has been a total failure and may have caused or is contributing to the poor water quality in the Cabrillo recreational areas. The present dredge dumping operation places Main Channel dredged material over old existing fill plus in an additional 50 acres that was added to the Shallow Water Habitat Zone necessary to accommodate the estimated 3 million cubic yards of dredge; this accelerated dumping activity appears to have aggravated existing water quality problems.

In previous years fill material was barged over from Catalina Island and dumped in the designated zone, this activity eventually isolated the Pier from the ocean thus creating a very large “dead zone” of a few hundred acres (note Grey area of Chart). Visiting ocean fish bypassed the Pier and the Shallow Water Habitat area as they proceeded along the raised seafloor wall into the West Channel and the Cabrillo Marina where they found a well-stocked buffet; the few ocean fish that showed up around the Pier are/were most likely lost or sick.

The ever upward growing Shallow Water Habitat fill material has essentially formed a buffer zone between the ocean, the Pier and the Cabrillo Inner Beach recreational area eliminating useful amounts of fresh seawater circulation thus encouraging the growth of microalgae and pathogens. What remains is a vast underwater desert-like wasteland devoid of fish and other aquatic species.

A once prominent feature in this locale is the Cabrillo Fishing Pier (note Chart). Years ago a very productive well used recreation area, a section of the Pier was actually reserved for students who were bused-in, a fishing field trip about local fish and fishing, the Pier was a proud asset of the San Pedro community. It remains well maintained but now something of a joke, a high maintenance “white elephant”, great for walking but leave your fishing pole home.

As a result of poor original planning (lack of proper circulation) and subsequent habitat filling operations the Cabrillo Beach Youth Waterfront (CBYW) has become seagrass congested to the extent that swimming is prohibited and watersports are limited to kayaking and other small boat activities. Cabrillo Inner Beach water has for years received, on average, “F” grades for water quality; this is primarily due to a heavy and on-going concentration of seagull feces, poor tidal flow and almost zero fresh ocean water circulation. An obvious but expensive fix often suggested but never implemented included dredging in a deep water channel. Over the years million$ have been invested in various alternative efforts with little or no improvement, just a few years ago almost all of the Inner Beach sand to the high tide water line was replaced resulting in an attractive inviting beach, unfortunately the adjacent water is usually a sick brown color, the brown material is not the normal suspended sand in surf but is decaying matter and pathogen contamination, which of course is why the water is “F” rated.

The water quality is so bad that Cabrillo Beach Lifeguards are not allowed to enter the water, it would be in violation of their Medical Insurance, but not a problem, the public is protected: Cabrillo Beach Lifeguards undergo rigorous training in Roping, to qualify for Cabrillo Inner Beach Service a Lifeguard must be able to lasso a toddler 15 paces offshore and drag him/her to the dry beach within one minute.  

Only recently have comments such as “bird droppings” and “poor water circulation” been publically mentioned as a probable cause, but along with that revelation came a ridiculous off-the-wall suggestion to “install a Pump Circulation System”, fortunately common sense prevailed and that plan was cancelled. Today the idea of bringing in a wide deep water channel would be economically prohibitive and impractical due to the on-going dredge dumping operation which has essentially blocked easy access to the deep main channel.  Cleaning up Cabrillo Inner Beach water is and will most likely remain a back-burner issue that may never be resolved.

Water in the Cabrillo Marinas and the West Channel has been spared the Inner Beach water problems by virtue of the wide deep channel running up thru the West Channel to the 22nd Street Landing, in addition the Marinas are in a sense kind of isolated from the Inner Beach and the seagrass congested CBYW area by a rock Quay Wall. Pathogens common in the Inner Beach area are absent in the Marina by virtue of trace elements of copper slowly leached 24/7/360 into the Marina from boat bottom copper based paint.

The underwater geography has encouraged costal fish to migrate to the Marina which has become a nursery for many fish species including the Garibaldi, the California State Fish, and a protected species. The current dumping operation is displacing ocean water with solid dredge material at the head of the 22nd St./West Channel entrance; this on-going underwater material build-up and channel narrowing is changing the hydrodynamics of the area. The previous cleansing tidal flow is now being restricted thus reducing the once vigorous outgoing “flushing” action; the key to a cleansing flush is the outgoing tide which is now “buffered” to a point that soon the area will no longer enjoy the necessary daily volume exchange of fresh ocean water. 

Cabrillo Marina is an Aquatic Ecosystem/Salt Water Aquarium; a healthy saltwater aquarium requires a balance between water quality, sunlight and nutrients, obviously sunlight at the Marina cannot be controlled however in this instance it is not the most important parameter. Nutrient input (from land runoff) is very important; that problem is under control. To minimize and control suspended green algae in a saltwater aquarium requires a weekly water change of at least 10% to 15%. Water chemistry in the Marina is a bit more complicated due to boat engine wet exhaust systems, the expelled exhaust gas and residue essentially goes into solution, to off-set that influx would require an additional fresh seawater water exchange. This infusion into a Marina would be via tide cycles of fresh seawater. As dredge dumping continues water exchange is becoming more restricted and now limited to those occasions when a very high tide is followed by a very low tide (King Tides). For the most part regular tide action today simply moves water back and forth between the Marina and the Outer Harbor where the water is mixed with water disturbed by the dumping operation and the upwelling nutrients. Said again the Marina may not be seeing sufficient fresh seawater to maintain a safe algae balance.

As of October 2012 the water in the Marina/22ndStreet Landing/West Channel remained heavy with suspended debris and microalgae.

This unsightly opaque green and sometimes green/black water is in stark contrast to the clear snorkeling water visibility of just a few years ago. The following polarized telephoto pictures were taken 20/30 feet above the surface; subjects are 3 to 4 feet below the surface. That level of visibility is no longer available.


At present levels the debris and green microalgae saturated water is not harmful. Anchovy hatchlings and Opaleye feed on algae and their numbers are noticeably increasing,  however the overall unfavorable appearance and reduced water visibility has many boaters asking questions and has discouraged back-of-the-boat fishing, swim parties, snorkeling and other in-water sports once popular Marina activities.

Incoming and outgoing tides follow the path of least resistance, as the Chart indicates the obvious path of least resistance is from from the ocean past the Lighthouse and up the open-ended Main Channel. Water entering the Cabrillo Basin, the Marina and the West Channel encounters noticeable resistance from the fill material. As the program continues and the fill reaches maximum levels the Marina will see a reduced volume of fresh clean ocean water; the suspended green/brown microalgae will flourish, cycle and die leading to reduced oxygen levels and the potential for a fish die-off.

The rationale that prompted this investigation: Within the past few years water visibility in Cabrillo Marina has gone from very good to an opaque green and/or an opaque green/black resulting in limited observational and photographic visibility. This condition has complicated my business and hobby of designing and testing custom underwater video system, observation lighting systems and advanced FAD’s (fish attraction devices) for Fishery and Oceans Science Research and Educational programs. In the past preliminary research and ocean testing was undertaken from the convenience of my vessel and others berthed in Cabrillo Marina, only a short drive from my laboratory, today these tasks must be undertaken offshore (example: Catalina Emerald Bay) causing considerable delay, extra expense and in many instances preventing our participation in important tight schedule/limited budget research programs. Thus it was important to understand exactly what was going on, why has water visibility suddenly changed and is it a temporary or a permanent condition? 

An additional concern is the potential damage to the Marina aquatic species; Cabrillo Marina by virtue of clean fresh circulating ocean water evolved over many years into an aquatic ecosystem, a living aquarium accommodating many native ocean fish and other aquatic species and daily hosts large ocean predators seeking an easy meal. The Marina has become a sanctuary and nursery for many local fish species including in part anchovies, opaleye, mackerel, perch, smelt, halibut, bass, rays, skates, octopus, red and black crab and even a turtle. We understand and fully acknowledge that the Marina is first and foremost a “parking lot” for boats, it was designed for that specific purpose and boats do not care about water visibility, and the tenants were not guaranteed snorkeling quality water. The fact that this particular Marina evolved into a habitat and nursery for aquatic species was fortuitous. Would it not be in the best public interest to maintain that environment???

Depositing 3 million cubic yards of solid dredge material near the Marina/West Channel entrance and reducing the width of the entrance channel will displace over 600 million gallons of seawater; this will have a dramatic impact on Marina water circulation and will reduce the volume of fresh ocean water exchanged within the Marina. It would be unfortunate if circulation and water exchange volume drops below the levels necessary to sustain the Marina’s unique aquarium-like environment.

Technical Information: All pictures of organisms in this paper are alive and swimming in one drop of water in a Well Slide, they were collected using an empty water bottle by dipping into the Algae Bloom. The preferred professional method would use a 20um drag net with samples taken at various depths. Using a drag net will quickly collect many samples from many gallons of water rather than the few samples that may be available in a simple single 16 ounce surface scoop. Our main microscope is a moderate priced Trinocular Brightfield/Darkfield Compound Microscope w/LED lighting (cold LED lighting is best for live specimens) with upgraded Plan Achromatic Objective Lens’s and extra wide view high eye relief 10x eyepieces. This is a solid heavy and very stable microscope manufactured in Germany and sold on-line under the OMAX brand. In this investigation we did not use the Darkfield accessory. A professional laboratory microscope often used for plankton viewing would be an “Inverted Microscope”, at several times the price. The only problem we noted with our OMAX microscope is the quality of the prism, with the 40X & 62X objectives the split view directed to the camera revealed many optical flaws typically found in lower priced equipment, for our less professional look-see purpose we have been able to work around that problem. The microscope camera is a 10 Megapixels USB-2.0 Model MU1000 manufactured by ToupView (China) using the latest Sony CMOS sensors and chip technology, excellent camera software and support is provided by ToupView. We use IrfanView for pre-viewing captured still and videos and Adobe Photoshop for final photo editing. The computer is a fast high-end custom machine with an advanced graphics card feeding two high resolution high contrast 23” monitors offering very sharp on-screen digital image magnification. Image on-screen magnification and photo capture is dependent upon the camera and software. A smooth light touch microscope mechanical stage with large fine focus knobs are essential to facilitate  tracking, focus and capturing the live moving specimens. Expect to take many still pictures and many long videos before lucking out and capturing a single “Wow” photograph. Typically we eyeball a single drop of water in a well slide (uncovered) @ 200X using the 20X objective lens and 10X wide view eyepiece. If something interesting is noted we glass cover the slide and go to the 40X or 62X objective giving a 400X/620X optical view, center the specimen and use the computer monitor while scanning, focusing, tracking and image capture.


This program is on-going, comments are welcome:  

Addendum: Brown Tide Algae Bloom – Cabrillo Marina. Thursday October 11, 2012: A dark brown cloud engulfed most of the Marina; microscope pictures sent to were identified as the raphidophyte, Heterosigma akashiwo, which is not a dinoflagellate. Heterosigma akashiwo is a microscopic swimming marine alga that forms toxic surface aggregations and is considered a HAB (harmful algal bloom). The bloom lasted about 24 hours and it is not a frequent occurrence in the Marina. It may have come in with the tide however I’m guessing that it originated in the dump zone.

If the bloom dissipated in the Marina (as opposed to being carried back to the basin on the outgoing tide) the cells may have transformed into resting cysts on the bottom. Next year, when conditions are right the cells will re-emerge in the Marina, and will perhaps form another bloom, a continuing but infrequent cycle. Our previous algae bloom of Akashiwo sanguinium, a dinoflagellate, prey upon these little guys, in the event that tide, wind and current bring Akashiwo sanguinium cells into the Marina while the Heterosigma are blooming we will have a massive microscopic feeding frenzy making for an interesting microscope video:

Sample location: Cabrillo - LA-06               Heterosigma sanguinium

King Tides: From November 2012 (continuing thru February 2013) the California coastline experience a series of very high/very low tides known as “King Tides”. From January 9 to January 15 Cabrillo Marina saw nine consecutive King Tide days.  The peak of this activity was January 11, 2013 when the Marina low tide dipped to -1.7 feet, followed by a high tide of +7 feet.

The Cabrillo Marina area contains about 135 acres of surface water; a 7 foot high tide added approximately 300,000,000 gallons to the existing body of water, then a few hours later the new and old water mix flowed out with the low tide to a -1.7 level. No matter how you do the math we are talking about a major exchange of water. It was expected that this vigorous tidal shift would thoroughly flush the Marina of most of the debris and microalgae presently suspended in the water that has reduced eyeball visibility to a fuzzy foot and photographic visibility to a few inches. In prior years (based upon personal observations going back to 1991) this extreme tidal action should have cleared up the water and produced good visibility to about 8 feet or more.

The dumping operation left the Basin with a few million cubic yards of uncompact uneven dispersed material on the bottom with many small “hills and valleys”, the vigorous King Tides stirred up the bottom tending to level the area but at the same time disturbing tons of light weight debris that remains in suspension. Thus in this instance there was no noticeable change in water visibility, the water remained a dense green/brown heavy with suspended debris, the fine particle size and low molecular weight of much of the debris suggests that it may remain in suspension for many months after the dumping operation has been completed sometime in 2013. On the other hand the daily incoming tides churning and surging over the “fluid” basin bottom, now only 14’ deep, may keep these fine particles in suspension indefinitely? Not a happy thought…

These observations tend to support our theory that dumping millions of cubic yards of “processed” and “sterilized” main channel dredge material in the expanded Shallow Water Habitat Zone at the entrance to the Marina has changed the constitutes of the water and the hydrodynamics of the area to the extent that the tides simply move the water and debris back and forth between the Marina and the Basin area meaning that the Marina sees very little fresh seawater.

During the coming months as the water warms we expect to see an increase in suspended microalgae triggering a possible bloom w/reduced oxygen levels, if this coincides with the re-emergence of the Heterosigma akashiwo cysts now “sleeping” in the bottom sand it could set the stage for a potential fish die-off.