Caltrans’ emergency effort to stabilize the southbound Eureka Slough Bridge drew scrutiny last week as the California Coastal Commission reviewed the agency’s request for additional emergency authorization and heard concerns about wildlife disturbance near the construction zone.Shana Gray, North Coast District Deputy Director, reported to the Coastal Commission that deteriorated piles discovered during an April inspection prompted immediate safety measures, including shifting southbound Highway 101 traffic, installing monitoring devices, and beginning construction of a temporary work trestle spanning the slough.“The situation is active and still evolving,” Gray said. “Caltrans is in active communication with the National Marine Fisheries Service and Commission staff on these protective measures for seals, including the need for additional avoidance and minimization measures. Staff are working closely with Caltrans on this emergency situation, and we plan to report any further emergency actions to the Commission and the public.”In‑water work and pile driving began on July 7 after Caltrans declared the need for significant structural repairs, including repairs to compromised footings. A second emergency permit has not yet been authorized, and staff said they are still evaluating whether the proposed work is the minimum necessary to address the hazard.Environmental groups urged the commission to strengthen monitoring requirements for harbor seals that haul out near the mouth of the slough. Jennifer Savage of the Surfrider Foundation raised concerns about potential negative impacts on seals and other wildlife in the construction area.“We understand the emergency that there are deteriorated bridge piles requiring immediate safety action, but we do share the concerns that Humboldt Waterkeeper raised. I live a few miles from this bridge. I kayak near that slough. I walk my dog on the adjacent trail, so I know the area really well,” said Savage. “I appreciate staff’s update on the plans, as was just reported. I still want to highlight that two harbor seal haulouts sit within one kilometer of the work site in the Eureka Slough.”Savage shared recent pictures of the seals sitting on the shore of the slough and noted the work coincides with the molting period, when seals rely heavily on undisturbed haulouts.“The pile driving, the core drilling, the heavy machinery — it all generates acoustic and seismic disturbance that travels quickly underwater,” she said. And this work coincides with the start of the harbor seals’ molting period, when sight-faithful animals most depend on undisturbed haulout time.”Jen Kalt of Humboldt Waterkeeper raised concerns about repeated water flushes, which can increase stress and the risk of infection.“We understand the emergency nature of this situation; it’s been very concerning because the harbor seals, as we mentioned in our public comments, are in the very sensitive molting period, where if they get disturbed, they need to go back into the water continuously or frequently, more frequently than they should, which risks infection,” said Kalt. “The draft environmental impact report for this project, the actual bridge replacement project, includes a marine mammal protection plan and hydroacoustic monitoring plan to prevent level B harassment, which is changes in behavior. Caltrans seems to rely on seals moving to unaffected, suitable habitat in the bay, which, in itself, is level B harassment. So, just expecting the seals to relocate to get away from the noise — that is harassment and is really concerning.”Kalt mentioned pile driving has already begun under an emergency permit the Coastal Commission has not yet reviewed, and urged commissioners to closely examine Caltrans’ hydroacoustic and marine mammal protection plans to ensure impacts to nearby harbor seal haulouts are minimized.Cal Poly Humboldt Marine Biologist Dawn Goley urged the commission to require detailed hydroacoustic monitoring and real‑time reporting.“Harbor seals have high site fidelity and are among the most sensitive marine mammals to human disturbance,” said Goley. “They can’t simply relocate to another haulout because those sites are already occupied.”Goley questioned whether Caltrans has provided the required hydroacoustic monitoring plan to federal regulators and asked how the plan addresses marine mammals’ sensitivities to sound. The speaker said real‑time monitoring, clear reporting protocols and sound‑attenuation systems are critical as construction continues under an emergency permit.“These questions need to be urgently addressed to avoid disturbance and potential abandonment of important habitat for federally protected marine mammals,” said Goley.Caltrans spokesperson Myles Cochrane said trestle construction is underway along Highway 101 near Target to give contractor Myers and Sons access to stabilize one of the southbound bridge’s piers. The work, which includes installing new steel piling, is expected to continue through October. He said the agency is balancing structural repairs with environmental protections, noting that crews are maintaining traffic flow while conducting hydroacoustic monitoring, marine mammal surveys, and enforcing shutdown zones during in‑water pile work.“One of the main challenges in all this is keeping this work going in a sensitive environment while maintaining traffic flow along the busiest stretch of state highway in Humboldt County,” said Cochrane. “During in-water pile work, Caltrans is conducting hydroacoustic and marine mammal monitoring and maintaining a shutdown zone to minimize potential disturbance to harbor seals and other marine mammals.”Cochrane said the bridge remains open and safe for travel, with southbound lanes shifted slightly to accommodate construction.“Crews are doing a great job keeping traffic moving as the lanes on the southbound bridge are shifted over a bit. 101 in Eureka is open and safe for travel,” said Cochrane. “We appreciate the public’s patience and encourage drivers to slow down, stay alert, and cruise safely through the cone zone while this job goes on.”A segment of the Eureka Waterfront Trail beneath the bridge remains closed through mid‑October due to trestle construction. Commission staff said they will report back at the next hearing once the full scope of emergency work is understood.Read Original Article
